Click here MAX34451 PMBs 16-Channel VI Monitor an 12-Channel … · 2019. 10. 28. · MAX34451 Mus...

General DescriptionThe MAX34451 is a power-supply system manager that is capable of monitoring up to 16 different voltage rails or currents and is also capable of sequencing and margining up to 12 power supplies. The system manager monitors the power-supply output voltages and currents and constantly checks them for user programmable over and under threshold limits. If a fault is detected, the device automatically shuts down the system in an orderly fashion. The device can sequence the supplies in any order at both power-up and power-down. The device has the ability to close-loop margin the power-supply output voltages up or down to a user-programmable level. The device contains an internal temperature sensor and can support up to four external remote temperature sensors. Once configured, the device can operate autonomously without any host intervention.

Applications NetworkSwitches/Routers BaseStations Servers SmartGridNetworkSystems

Benefits and Features IntegrationEnablesManagementofMultiplePower

SuppliestoMaximizeSystemPerformance• 16 Channels of Voltage or Current Monitoring• 12ChannelsofSequencingandMargining(8PWM,4ExternalCurrentDACs(1xDS4424), andSequencing

• ExpandableChannelOperationwithParallel Devices

• RemoteGroundSensingImprovesMeasurementAccuracy

• ProgrammableUpandDownTime-Basedor Event-BasedSequencing

• DualSequencingLoops• ConfigurableCombinatorialLogicSupportingUpto16GPIsand20GPOs

• AutomaticClosed-LoopMargining• NoExternalClockingRequired• PMBus™-CompliantCommandInterface

Fast,ReliableControlandFaultDetectionImprovesSystemReliability• FastMinimum/MaximumThresholdExcursionDetection

• SupportsUpto5TemperatureSensors(1Internaland4Remote)

• FaultDetectiononAllTemperatureSensors• ReportsPeak,Minimum,andAverageLevelsforaNumberofParameters

• ProgrammableAlarmOutputs• On-BoardNonvolatileBlackBoxFaultLoggingandDefaultConfigurationSetting

I2C-/SMBus-CompatibleSerialBuswithBus Time-OutFunctionSimplifiesAdditionalTemperatureSensorsandDACstotheMAX34451

+3.0Vto+3.6VSupplyVoltageOrdering Information and Typical Operating Circuit appear at end of data sheet.

PMBus is a trademark of SMIF, Inc.

19-6642; Rev 9; 10/19

MAX34451 PMBus 16-Channel V/I Monitor and 12-Channel Sequencer/Marginer

EVALUATION KIT AVAILABLE

Click here for production status of specific part numbers.

https://www.maximintegrated.com/en/storefront/storefront.html

GeneralDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1BenefitsandFeatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1AbsoluteMaximumRatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8RecommendedOperatingConditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8PackageInformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 856TQFN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8ElectricalCharacteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9I2C/SMBusInterfaceElectricalSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12TypicalOperatingCharacteristics(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13PinConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14PinDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

ExpandedPinDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17BlockDiagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18DetailedDescription . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

PMBus/SMBusAddressSelect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23SMBus/PMBusOperation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

SMBus/PMBusOperationExamples. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24GroupCommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

GroupCommandWriteFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25ALERTandAlertResponseAddress(ARA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

AlertResponseAddress(ARA)ByteFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25HostSendsorReadsTooFewBits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HostSendsorReadsTooFewBytes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HostSendsTooManyBytesorBits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HostReadsTooManyBytesorBits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HostSendsImproperlySetReadBitintheSlaveAddressByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26UnsupportedCommandCodeReceived/HostWritestoaRead-OnlyCommand . . . . . . . . . . . . . . . . . . . . . . . . . 26InvalidDataReceived . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26HostReadsfromaWrite-OnlyCommand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26SMBusTimeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26PMBusOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27PMBusProtocolSupport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27DataFormat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

TABLE OF CONTENTS


www.maximintegrated.com Maxim Integrated 2

InterpretingReceivedDIRECTFormatValues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27SendingaDIRECTFormatValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28FaultManagementandReporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29PasswordProtection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Power-SupplySequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Dual-LoopSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Power-OnSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Power-OffSequencing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32SequencingExample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

MultipleDeviceConnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33SEQPinOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34SystemWatchdogTimer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34CRCMemoryCheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

PMBusCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35PAGE(00h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35OPERATION(01h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36ON_OFF_CONFIG(02h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38CLEAR_FAULTS(03h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40WRITE_PROTECT(10h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40DeviceConfigurationDataManagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40STORE_DEFAULT_ALL(11h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41RESTORE_DEFAULT_ALL(12h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41MFR_STORE_ALL(EEh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41MFR_RESTORE_ALL(EFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41MFR_STORE_SINGLE(FCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42MFR_CRC(FEh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42CAPABILITY(19h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42VOUT_MODE(20h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43VOUT_MARGIN_HIGH(25h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43VOUT_MARGIN_LOW(26h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43VOUT_SCALE_MONITOR(2Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43IOUT_CAL_GAIN(38h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44VOUT_OV_FAULT_LIMIT(40h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44VOUT_OV_WARN_LIMIT(42h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44VOUT_UV_WARN_LIMIT(43h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44VOUT_UV_FAULT_LIMIT(44h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

TABLE OF CONTENTS (continued)



IOUT_OC_WARN_LIMIT(46h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44IOUT_OC_FAULT_LIMIT(4Ah). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45OT_FAULT_LIMIT(4Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45OT_WARN_LIMIT(51h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45POWER_GOOD_ON(5Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45POWER_GOOD_OFF(5Fh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45TON_DELAY(60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45TOFF_DELAY(64h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45TON_MAX_FAULT_LIMIT(62h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46STATUS_WORD(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47STATUS_VOUT(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47STATUS_IOUT(7Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48STATUS_TEMPERATURE(7Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48STATUS_CML(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48STATUS_MFR_SPECIFIC(80h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49READ_VOUT(8Bh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50READ_IOUT(8Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50READ_TEMPERATURE_1(8Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50PMBUS_REVISION(98h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_ID(99h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_MODEL(9Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_REVISION(9Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_LOCATION(9Ch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_DATE(9Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_SERIAL(9Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_MODE(D1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50MFR_PSEN_CONFIG(D2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52DelayFunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_VOUT_PEAK(D4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_IOUT_PEAK(D5h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_TEMPERATURE_PEAK(D6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_VOUT_MIN(D7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_FW_SERIAL(E0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_IOUT_AVG(E2h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54




MFR_NV_LOG_CONFIG(D8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54MFR_FAULT_RESPONSE(D9h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

LOCALvs.GLOBALChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56GLOBALChannelsRespondtoFAULTn Assertion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56TemperatureFaultResponse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56FaultDetectionBeforePower-OnSequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57LoggingFaultsintoMFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57AlarmOutputFunctionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

MFR_FAULT_RETRY(DAh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61MFR_NV_FAULT_LOG(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61MFR_TIME_COUNT(DDh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64MFR_CHANNEL_CONFIG(E4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64MFR_TON_SEQ_MAX(E6h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68MFR_PWM_CONFIG(E7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68DelayFunction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70MFR_SEQ_CONFIG(E8h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70MFR_MARGIN_CONFIG(DFh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Power-SupplyMarginingOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71MarginingFaults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72DC_DACValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72PWM/DACMarginingComponentSelection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

TemperatureSensorOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73Applications Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

VDD, VDDA,andREG18Decoupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Open-DrainPins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Keep-AliveCircuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74ConfigurationPort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Resistor-DividersandSourceImpedanceforRSnInputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74ProtectingInputPins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74ExposedPadGrounding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Typical Operating Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75RevisionHistory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76




Figure1.PMBus/SMBusAddressSelect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Figure2.SequenceControlLogic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Figure3.SequencingExample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Figure4.MultipleMAX34451HardwareConnections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Figure5.ON_OFF_CONFIGLogicalControl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39Figure6.DeviceConfigurationDataManagement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Figure7.StatusRegisterOrganization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46Figure8.MFR_PSEN_CONFIGFunctionalLogic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53Figure9.Input-to-OutputDelayAction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54Figure10.MFR_FAULT_RESPONSEOperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Figure11.MFR_NV_FAULT_LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61Figure12.MFR_CHANNEL_CONFIGCommand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Figure13.MFR_PWM_CONFIGFunctionalLogic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Figure14.MarginingHardwareConfigurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Table1.PMBusPAGEtoPin/ResourceMapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Table2.DeviceChannelCapabilitiesandOptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Table3.PMBusCommandCodes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Table3.PMBusCommandCodes(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Table3.PMBusCommandCodes(continued) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Table4.PMBus/SMBusSerial-PortAddress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Table5.PMBusCommandCodeCoefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Table6.CoefficientsforDIRECTFormatValue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Table7.Fault-MonitoringStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Table8.OPERATIONCommandSequenceControlOptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Table9.PAGE(00h)Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35Table10.OPERATION(01h)CommandBytewithPAGE=0–11(WhenBit3ofON_OFF_CONFIG=1) . . . . . . . . 36Table11.OPERATION(01h)CommandBytewithPAGE=255(WhenBit3ofON_OFF_CONFIG=1) . . . . . . . . . 37Table12.OPERATION(01h)CommandByte(WhenBit3ofON_OFF_CONFIG=0) . . . . . . . . . . . . . . . . . . . . . . . 37Table13.ON_OFF_CONFIG(02h)CommandByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Table14.WRITE_PROTECT(10h)CommandByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

LIST OF FIGURES

LIST OF TABLES



Table15.MemoryTransferPMBusCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Table16.MFR_CRC(FEh)CommandByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Table17.CAPABILITY(19h)CommandByte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Table18.VOUT_SCALE_MONITOR(2Ah)Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43Table19.STATUS_WORD(79h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Table20.STATUS_VOUT(7Ah) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47Table21.STATUS_IOUT(7Bh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Table22.STATUS_TEMPERATURE(7Dh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Table23.STATUS_CML(7Eh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48Table24.STATUS_MFR_SPECIFIC(80h)(forPAGES0–11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Table25.STATUS_MFR_SPECIFIC(forPAGE255) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Table26.MFR_MODE(D1h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51Table27.MFR_PSEN_CONFIG(D2h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Table28.MFR_NV_LOG_CONFIG(D8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Table29.FaultMonitoringStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Table30.MFR_FAULT_RESPONSE(D9h). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Table31.ALARM_CONFIGCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Table32.MFR_FAULT_RESPONSECodesforGLOBALChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60Table33.MFR_FAULT_RESPONSECodesforLOCALChannels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60Table34.MFR_NV_FAULT_LOG(DCh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62Table35.MFR_CHANNEL_CONFIG(E4h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65Table36.Fault-MonitoringStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Table37.MFR_PWM_CONFIG(E7h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69Table38.MFR_SEQ_CONFIG(E8h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71Table39.MFR_MARGIN_CONFIG(DFh). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72Table40.Power-SupplyDACOutputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72Table41.DS75LVAddressPinConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74Table42.MFR_TEMP_SENSOR_CONFIG(F0h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

LIST OF TABLES (continued)



VDD and VDDA to VSS .........................................-0.3Vto+4.0VRSG0andRSG1toVSS ......................................-0.3Vto+0.3VAllOtherPinsExceptREG18 RelativetoVSS ....................................-0.3Vto(VDD+0.3V)*

REG18toVSS ......................................................-0.3Vto+2.0V

ContinuousPowerDissipation(TA=+70°C) TQFN(derate27.8mW/°Cabove+70°C)...............2222.2mW

OperatingTemperatureRange ........................... -40°Cto+85°CStorageTemperatureRange ............................ -55°Cto+125°CLeadTemperature(soldering,10s) .................................+260°CSolderingTemperature(reflow) .......................................+260°C

(TA=-40°Cto+85°C,unlessotherwisenoted.)

*Subject to not exceeding +4.0V.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSVDDOperatingVoltageRange VDD (Note1) 3.0 3.6 V

InputLogic1(ExceptI2CandGPInPins) VIH1

0.7xVDD

VDD+0.3 V

InputLogic0(ExceptI2CandGPInPins) VIL1 -0.3 +0.3xVDD V

InputLogic1:SCL,SDA, MSCL,MSDA VIH2 2.1 VDD+0.3 V

InputLogic0:SCL,SDA, MSCL,MSDA VIL2 -0.3 +0.8 V

InputLogic1(GPInPins) VIH3 Minimum pulse width 5ms 1.5 VDD+0.3 V

InputLogic0(GPInPins) VIL3 Minimum pulse width 5ms -0.3 +1.0 V

SourceImpedancetoRSn

ADC_TIME[1:0]=00 1

kΩADC_TIME[1:0]=01 5

ADC_TIME[1:0]=10 10

ADC_TIME[1:0]=11 20

VDDRiseTime From0Vto3.0V 4 ms

VDDSourceImpedance 10 Ω

PACKAGE TYPE: 56 TQFNPackageCode T5677+2OutlineNumber 21-0144LandPatternNumber 90-0043

Absolute Maximum Ratings

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Recommended Operating Conditions

Package Information

Forthelatestpackageoutlineinformationandlandpatterns(footprints),gotowww.maximintegrated.com/packages.Notethata“+”,“#”,or“-” inthepackagecodeindicatesRoHSstatusonly.Packagedrawingsmayshowadifferentsuffixcharacter,butthedrawingpertainstothepackageregardlessofRoHSstatus.



http://pdfserv.maximintegrated.com/package_dwgs/21-0144.PDF

http://pdfserv.maximintegrated.com/land_patterns/90-0043.PDF

http://www.maximintegrated.com/packages

(VDD and VDDA=3.0Vto3.6V,TA=-40°Cto+85°C,unlessotherwisenoted.TypicalvaluesareatVDD/VDDA=3.3V,TA=+25°C.)(Note2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSGENERAL

SupplyCurrentICPU (Note3) 12

mAIPROGRAM 18

SystemClockError fERR:MOSC+25°C<TA<+85°C -3 +3

%-40°C<TA<+25°C -4 +4

OutputLogic-Low(ExceptI2CPins) VOL1 IOL=4mA(Note1) 0.4 V

OutputLogic-High(ExceptI2CPins) VOH1 IOH =-2mA(Note1) VDD-0.5 V

OutputLogic-Low:SCL,SDA,MSCL,MSDA VOL2 IOL=4mA(Note1) 0.4 V

SCL,SDA,MSCL,MSDALeakage ILI2C VDD=0Vorunconnected ±5 µA

CONTROL0Threshold 2.048 V

CONTROL0Hysteresis 50 mV

ADCADCBitResolution 12 Bits

ADCConversionTime ADC_TIME[1:0]=00 1000 ns

ADCFullScale VFS TA=0°Cto+85°C 2.032 2.048 2.064 V

ADCMeasurementResolution VLSB 500 µV

RSnInputCapacitance CRS 15 pF

RSnInputLeakage ILRS 0V<VRSn<2.1V ±0.25 µA

ADCIntegralNonlinearity INL ±1 LSB

ADCDifferentialNonlinearity DNL ±1 LSB

TEMPERATURE SENSORInternal Temperature-MeasurementError TA=-40°Cto+85°C ±2 °C

Electrical Characteristics



(VDD and VDDA=3.0Vto3.6V,TA=-40°Cto+85°C,unlessotherwisenoted.TypicalvaluesareatVDD/VDDA=3.3V,TA=+25°C.)(Note2)

Note 1: All voltages are referenced to ground. Current entering the device are specified as positive and currents exiting the device are negative.

Note 2: Limitsare100%productiontestedatTA=+25°C.Limitsovertheoperatingtemperaturerangeandrelevantsupplyvoltagerangeareguaranteedbydesignandchacterization.

Note 3: Thisdoesnotincludepininput/outputcurrents.Note 4: Guaranteedbydesign.Note 5: Theround-robinthresholdexcursionratecanbechangedwiththeADC_AVERAGEandADC_TIMEbitsinMFR_MODE

from16µs(noaveragingand1µsconversion)to1024µs(8xaveragingand8µsconversion).

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSFLASH

FlashEndurance NFLASH Note3 20,000 WriteCycles

DataRetention TA=+50°C(Note4) 100 Years

STORE_DEFAULT_ALL, MFR_STORE_ALLWriteTime 80 ms

RESTORE_DEFAULT_ALL WithMFR_STORE_SINGLEdata 105 msRESTORE_DEFAULT_ALLorMFR_RESTORE_ALL WithoutMFR_STORE_SINGLEdata 500 µs

MFR_STORE_SINGLE WriteTime 310 µs

MFR_NV_FAULT_LOG WriteTime Writing1faultlog 11 ms

MFR_NV_FAULT_LOG DeleteTime Deletingallfaultlogs 200 ms

MFR_NV_FAULT_LOG Overwrite Time 40 ms

TIMING OPERATING CHARACTERISTICS

Round-RobinVoltageandCurrentSampleRate

Thresholdexcursion(Note5) 64 µs

Datacollection 5 ms

TemperatureSampleRate 1000 ms

DeviceStartupTimeWithMFR_STORE_SINGLEdata 170

msWithoutMFR_STORE_SINGLEdata 90

PWMFrequency PWMpower-supplymargining 312.5 kHz

PWMResolution PWMpower-supplymargining 8 Bits

Electrical Characteristics (continued)



(VDD and VDDA=3.0Vto3.6V,TA=-40°Cto+85°C,unlessotherwisenoted.TypicalvaluesareatVDD/VDDA=3.3V,TA=+25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSSCLClockFrequency fSCL 10 400 kHz

MSCLClockFrequency fMSCL 100 kHz

BusFreeTimeBetweenSTOPandSTARTConditions tBUF 1.3 µs

HoldTime(Repeated) STARTCondition tHD:STA 0.6 µs

LowPeriodofSCL tLOW 1.3 µs

HighPeriodofSCL tHIGH 0.6 µs

DataHoldTime tHD:DATReceive 0

nsTransmit 300

DataSetupTime tSU:DAT 100 ns

StartSetupTime tSU:STA 0.6 µs

SDAandSCLRiseTime tR 300 ns

SDAandSCLFallTime tF 300 ns

StopSetupTime tSU:STO 0.6 µs

ClockLowTimeout tTO 25 27 35 ms

SCL

NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN).

SDA

STOP START REPEATEDSTART

tBUF

tHD:STA

tHD:DAT tSU:DAT

tSU:STO

tHD:STAtSP

tSU:STAtHIGH

tR

tFtLOW

I2C/SMBus Interface Electrical Specifications

I2C/SMBus Timing



(VDD=3.3VandTA=+25°C,withoutMFR_STORE_SINGLEdata,unlessotherwisenoted.)

FAULT PINS DURING POWER-UP

MAX

3445

1 to

c04

20ms/div

FAULT2

FAULT02V/div

VDD

GPOn OUTPUT PINS CONFIGURED DURING POWER-UP (ALL PINS CONFIGURED

TO BE PUSH-PULL ACTIVE-HIGH)

MAX

3445

1 to

c05

20ms/div

ALARM

2V/div

PG

VDD

GPO

ALARM OPERATION

PG OPERATION

FORCE GPO ASSERTION

SUPPLY CURRENT vs. TEMPERATURE

MAX

3445

1 to

c01

TEMPERATURE (°C)

I DD

(mA)

8060-20 0 20 40

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

10.0-40 100

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX

3445

1 to

c02

VDD (V)

I DD

(mA)

3.53.43.1 3.2 3.3

10.5

11.0

11.5

12.0

12.5

13.0

13.5

14.0

10.03.0 3.6

TA = +85°C

TA = +25°C

TA = -40°C

PSENn OUTPUTS DURING POWER-UP

MAX

3445

1 to

c03

20ms/div

PSEN1

PSEN0

VDD

THE PSENn PINS POWER UP IN A HIGH-IMPEDANCE STATE

TON_DELAY = 0ms

TON_DELAY =5ms

THE CONTROL n PIN IS ASSERTEDWHEN POWER IS APPLIED

2V/div

Typical Operating Characteristics


Maxim Integrated 12www.maximintegrated.com

(VDD=3.3VandTA=+25°C,withoutMFR_STORE_SINGLEdata,unlessotherwisenoted.)

ALERT PIN DURING POWER-UPM

AX34

451

toc0

6

400µs/div

ALERT

VDD1V/div

RST PIN DURING POWER-UP

MAX

3445

1 to

c07

400µs/div

VDD1V/div

RST

FILTERED MARGINING VOLTAGE vs. TIME

MAX

3445

1 to

c08

40ms/div

100mV/div

IDD vs. TIME DURING A NONVOLATILE LOG WRITE

MAX

3445

1 to

c09

2ms/div

IDD

5mA/div

0mA

2V/div

FAULTn

IDD vs. TIME DURING A NONVOLATILE LOG WRITE WITH OVERWRITE ENABLED

MAX

3445

1 to

c10

4ms/div

IDD

5mA/div

0mA

2V/div

FAULTn

Typical Operating Characteristics (continued)


Maxim Integrated 13www.maximintegrated.com

PIN* NAME TYPE** FUNCTION

1RS4 AI ADCVoltage-SenseInput4.ConnecttoVSS if unused.GPI4 AI General-PurposeInput4.ConnecttoVSS if unused.





6 CONTROL1 DI Power-SupplyMasterOn/OffControlInput1.Activeloworactivehighbasedon ON_OFF_CONFIGcommand.ConnecttoVSS if unused.

TOP VIEW

MAX34451

TQFN

15

17

16

18

19

20

21

22

23

24

25

26

27

28

SDA+ SCL

VDD

REG18

PSEN10/GPO10/FAULT2

RS14/GPI14

MSCL

MSDA

N.C.

PWM0/GPO12

PWM1/GPO13

PWM2/GPO14

PWM3/GPO15

PWM4/GPO16

RS5/GPI5

RS6/GPI6

RS7/GPI7

RS8/GPI8

RS9/GPI9

RS10/GPI10

RS11/GPI11

RS12/GPI12

PSEN9/GPO9

RS13/GPI13

PSEN8/GPO8

PSEN7/GPO7

PSEN6/GPO6

PSEN5/GPO5

48

47

46

45

44

43

54

53

56

55 EP/VSS

52

51

50

49

1 2 3 4 5 6 7 8 9 10 11 12 13 14

42 41 40 39 38 37 36 35 34 33 32 31 30 29

RST

PSEN

11/G

PO11

/SEQ

RS15

/GPI

15

CONT

ROL0

FAUL

T0V SS

N.C.

V DDA

CONT

ROL1

RS0/G

PI0

RS1/G

PI1

RS2/

GPI2

RS3/

GPI3

RS4/

GPI4

ADDR

ALER

T

PWM5

/GPO

17

PWM6

/GPO

18

PWM7

/GPO

19/F

AULT

1

RSG0

N.C.

RSG1

N.C.

PSEN

0/GP

O0

PSEN

1/GP

O1

PSEN

2/GP

O2

PSEN

3/GP

O3

PSEN

4/GP

O4

Pin Configuration

Pin Description



PIN* NAME TYPE** FUNCTION7 VDDA Power AnalogSupplyVoltage.BypassVDDA to VSSwith0.1µF.ConnecttoVDD.8 N.C. — NoConnection.Donotconnectanysignaltothispin.9 VSS Power GroundReference.MustbeconnectedtoEP(exposedpad).

10 FAULT0 DIO FaultInput/Output0.Open-drain,active-lowI/O.SeetheExpanded Pin Description section for more details.

11 CONTROL0 AI Power-SupplyMasterOn/OffControlInput0.Activeloworactivehighbasedon ON_OFF_CONFIGcommand.ConnecttoVSS if unused.

12 RST DIO Active-LowResetInput/Output.Containsaninternalpullup.

13

PSEN11 DO Power-SupplyEnable11.SeetheExpanded Pin Description section for more details.GPO11 DO General-PurposeOutput11

SEQ DIO SequencingInput/Output.Open-drain,active-lowI/O.Thispinisusedasahandshakesignal to coordinate sequencing in systems using multiple devices.


15 SDA DIO I2C/SMBus-CompatibleInput/Output.Open-drainoutput.16 SCL DIO I2C/SMBus-CompatibleClockInput/Output.Open-drainoutput.17 VDD Power DigitalSupplyVoltage.BypassVDD to VSSwith0.1µF.ConnecttoVDDA.

18 REG18 Power RegulatorforDigitalCircuitry.BypasstoVSSwith1µFand10nF(500mΩmaximumESR).Donotconnectothercircuitrytothispin.

19

PSEN10 DO Power-SupplyEnable10.SeetheExpanded Pin Description section for more details.GPO10 DO General-PurposeOutput10

FAULT2 DIO FaultInput/Output2.Open-drain,active-lowI/O.SeetheExpanded Pin Description section for more details.


21 MSCL DIO Master I2CClockInput/Output.Open-drainoutput.22 MSDA DIO Master I2CDataInput/Output.Open-drainoutput.23 N.C. — NoInternalConnection

24PWM0 DO PWMMarginOutput0.SeetheExpanded Pin Description section for more details.GPO12 DO General-PurposeOutput12





Pin Description (continued)





30 ALERT DO Alert Output. Open-drain, active-low output.

31 ADDR DISMBusSlaveAddressSelect.Thispinissampledondevicepower-uptodeterminetheSMBusaddress.SeethePMBus/SMBus Address Select section for details on how to strap this pin to select the proper slave address.


33

PWM7 DO PWMMarginOutput7.SeetheExpanded Pin Description section for more details.GPO19 DO General-PurposeOutput19

FAULT1 DIO FaultInput/Output1.Open-drain,active-lowI/O.SeetheExpanded Pin Description section for more details.

34 RSG0 AI Remote-SenseGroundforRS0/GPI0toRS3/GPI3andRS12/GPI12toRS15/GPI15.35 N.C. — NoInternalConnection36 RSG1 AI Remote-SenseGroundforRS4/GPI4toRS11/GPI11.37 N.C. — NoInternalConnection

38PSEN0 DO Power-SupplyEnable0.SeetheExpanded Pin Description section for more details.GPO0 DO General-PurposeOutput0














*All pins except the power pins, ALERT, and ADDR are high impedance during device power-up and reset.**AI = Analog input, AO = Analog output, DI = Digital input, DIO = Digital input/output, and DO = Digital output.










— EP/VSS Power ExposedPad(BottomSideofPackage).Mustbeconnectedtolocalground. Theexposedpadisthegroundreference(VSS)forthedevice.

PIN FUNCTION

PSEN0–PSEN11

ThePSEN0–PSEN11outputsareprogrammablewiththeMFR_PSEN_CONFIGcommandforeitheractive-high or active-low operation and can be either open drain or push-pull. If not used for power-supply enables, theseoutputscanberepurposedasgeneral-purposeoutputsusingtheMFR_PSEN_CONFIGcommand.Ifthese pins are used to enable power supplies, it is highly recommended that they have external pullups or pulldownstoforcethesuppliesintoanoffstatewhenthedeviceisnotactive.

PWM0–PWM7ThePWM0–PWM7outputsarehighimpedancewhenthemarginingisdisabled.A100%dutycycleimpliesthe pins are continuously high. If not used for margining, these pins can be repurposed as general-purpose outputswiththeMFR_PWM_CONFIGcommand.

FAULT0–FAULT2

The FAULT0–FAULT2 pins operate independently. Any global channel can be enabled with the MFR_FAULT_RESPONSEcommandtoassertoneormoreoftheFAULTn signals. Also, each global channel can be enabled to shut down when one or more of the FAULTn signals asserts. These pins are used to provide hardware control for power supplies across multiple devices. These outputs are unconditionally deasserted while RST is asserted or the device is power cycled. After device reset and upon device power-up, these outputs are pulled low immediately after program recall and held low until monitoring starts. Once monitoring starts, the FAULTn signals are released if no enabled faults are present.


Expanded Pin Description



PMBusCONTROL ANDMONITORING

ENGINE

PMBusINTERFACE

ENABLEFAULT0

PWM7GPO19FAULT1

PWM0–PWM6GPO12–GPO18

PSEN0–PSEN9GPO0–GPO9

ENABLE

SMBusMASTER

MSDA

MSCL

MIN/MAXAND AVERAGE

RESULTS

ADCRESULTS

SRAM

NV FAULTLOG

NVCONFIGURATION

SEQUENCINGENGINE

SAMPLEAVERAGING

MAX34451

TEMPSENSOR

VREF2.048V

AUTOSEQUENCER

12-BIT1MspsADC

MUX

8

VOLTAGE/CURRENT/TEMPERATURE

SMBusSLAVE

POWERCONTROL

1.8VVREG

SDA

SCL

ALERT

ADDR

RST

VDD

REG18

VSS

PULLUP

CONTROL1

CONTROL0

VDDA

2.048V

THRESHOLD EXCURSIONS

DIGITAL COMPARATORS

UNDERVOLTAGE WARNINGUNDERVOLTAGE FAULT

OVERVOLTAGE WARNINGOVERVOLTAGE FAULT

POWER–GOOD ONPOWER–GOOD OFF

OVERTEMPERATURE WARNINGOVERTEMPERATURE FAULT

GPI LOGIC ACTIVE–HIGHGPI LOGIC ACTIVE–LOW

SEQ

FAULT2

SEQUENCING

ENABLE

ENABLE AND

ALARMS

POWER-SUPPLY ENABLE

PINFUNCTION

SELECT

ALARMS

POWER GOOD/GPI

MARGINING CONTROL

FAULT1

FAULT0

RS0–RS3/RS12–RS15GPI0–GPI3/GPI12–GPI15

8RS4–RS11

GPI4–GPI11

RSG0

RSG1

16

16

16

16

10

ENABLE AND

ALARMS

ENABLE

PULSE-WIDTH MODULATOR PINFUNCTION

SELECT7

16

16

PSEN10GPO10FAULT2

PSEN11GPO11SEQ

Block Diagram



Detailed DescriptionThe MAX34451 is a highly integrated system monitor with functionality to monitor up to 16 different voltages or currents and to sequence and close-loop margin up to 12 power supplies. It also supports local and remote thermal sensing.The power-supply manager monitors the power- supply output voltage and current and constantly checks for user-programmable overvoltage, undervoltage, and overcurrent thresholds. It also has the ability to margin the power-supply output voltage up or down by a user-programmable level. The margining is performed in a closed-loop arrangement, whereby the device automati-cally adjusts aPWMsignal or an external currentDAC

output and then measures the resultant output voltage. The power-supply manager can also sequence the supplies in any order at both power-up and power-down.Thermal monitoring can be accomplished using up to five temperature sensors including an on-chip temperature sensor and up to four external remote DS75LV digitaltemperaturesensors.Communicationswith theDS75LVtemperature sensors is conducted through a dedicated I2C/SMBusinterface.The device provides ALERT and FAULTn output signals. Host communications are conducted through aPMBus-compatible communications port.See Table 1 and Table 2 for more details on specific device operation.

Table 1. PMBus PAGE to Pin/Resource Mapping

PMBus PAGE

PIN NAMERSn/GPIn

(16 AVAILABLE)PSENn/GPOn

(12 AVAILABLE)PWMn/GPOn

(8 AVAILABLE)

VOLTAGE OR

CURRENT MONITOR

GENERAL-PURPOSE

INPUT (GPI)

PIN

POWER-SUPPLY ENABLE(PSEN)

GENERAL-PURPOSE OUTPUT

(GPO)

PIN

PWM MARGIN OUTPUT(PWM)

GENERAL-PURPOSE OUTPUT

(GPO)

PIN

0 RS0 GPI0 5 PSEN0 GPO0 38 PWM0 GPO12 241 RS1 GPI1 4 PSEN1 GPO1 39 PWM1 GPO13 252 RS2 GPI2 3 PSEN2 GPO2 40 PWM2 GPO14 263 RS3 GPI3 2 PSEN3 GPO3 41 PWM3 GPO15 274 RS4 GPI4 1 PSEN4 GPO4 42 PWM4 GPO16 285 RS5 GPI5 56 PSEN5 GPO5 43 PWM5 GPO17 296 RS6 GPI6 55 PSEN6 GPO6 44 PWM6 GPO18 327 RS7 GPI7 54 PSEN7 GPO7 45 PWM7 GPO19 338 RS8 GPI8 53 PSEN8 GPO8 46

Margin capability provided through theexternalDS4424

9 RS9 GPI9 52 PSEN9 GPO9 4810 RS10 GPI10 51 PSEN10 GPO10 1911 RS11 GPI11 50 PSEN11 GPO11 1312 RS12 GPI12 49

CanmonitorvoltageorcurrentorbeassignedasGPI13 RS13 GPI13 4714 RS14 GPI14 2015 RS15 GPI15 14



Table 2. Device Channel Capabilities and Options

MAX34451CHANNEL

PMBus COMMAND

PAGECHANNEL CAPABILITIES

0–7 0–7

Voltage Monitor/Sequence/Margin/GPO Option:PinsRSn/GPIn,PSENn,andPWMn(wheren=0–7)haveaone-to-oneassociationforeachchannelthatmonitorsforvoltage(RSn)andcanbeusedtosequence(PSENn)andmargin(PWMn)thepowersupply.Thevoltagemonitoredonthischannelcanalsobeconfiguredtodetermine a power-good state. If not required for either sequencing or margining, the associated PSENnandPWMnoutputscanberepurposedasGPOnoutputsthatcaneitherindicatealogiccombinationofpower-good(PG)andGPIstatesorreportalarms.Current Monitor/GPO Option:IftheRSn/GPIninputisusedtomonitorcurrent,thenthechannelisnotusedtosequenceormargin.TheassociatedPSENnandPWMnoutputscanberepurposedasGPOnoutputsthatcaneitherindicatealogiccombinationofpower-good(PG)andGPIstatesorreportalarms.GPI/GPO Option:IftheRSn/GPIninputisconfiguredasageneral-purposeinput(GPI),itcanbeusedasaterminalogiccombinationtodetermineapower-good(PG)stateandassertaGPOnoutputoractasaconditiontoallowapowersupplytobeenabled.TheassociatedPSENnandPWMnoutputscanberepurposedasGPOnoutputsthatcanindicatepower-good(PG)statesorreportalarms.

8–11 8–11

Same as Channels 0–7 Except No PWM Outputs:PinsRSn/GPIn,andPSENn(wheren=8–11)arethesameaschannels0–7,exceptthePWMnoutputsforthesechannelsdonotexistandinsteadthedeviceusesanexternalDS4424currentDAC(connectedtothemasterI2Clocalbus)tomarginthepowersupplies.ThesechannelscanalsobeusedtomonitorcurrentorbeusedasGPIninputsjustlikechannels0–7.

12–15 12–15

PinsRSn/GPIn(wheren=12–15)cannotbeusedtocontrolsequencingorformargining.Voltage Monitor Option:Monitorvoltageincludingchannelpower-good(PG)andcanalsobeconfiguredtoshutdownoneor more power supplies if a fault occurs.Current Monitor Option:Monitorcurrentandcanbeconfiguredtoshutdownoneormorepowersuppliesifafaultoccurs.GPI Option:Asageneral-purposeinput(GPI),canbeusedasaterminalogiccombinationtodetermineapower-good(PG)stateandassertaGPOnoutputoractasaconditiontoallowapowersupplytobe enabled.



Table 3. PMBus Command Codes

CODE COMMAND NAME TYPE

PAGENO. OF BYTES

FLASH STORED/LOCKED(NOTE 2)

DEFAULT VALUE

(NOTE 2)0–11 12–15 16–20 255

(NOTE 1)

00h PAGE R/Wbyte R/W R/W R/W R/W 1 N/N 00h01h OPERATION R/Wbyte R/W W 1 N/N 00h02h ON_OFF_CONFIG R/Wbyte R/W R/W R/W R/W 1 Y/Y 1Ah03h CLEAR_FAULTS Sendbyte W W W W 0 N/N —10h WRITE_PROTECT R/Wbyte R/W R/W R/W R/W 1 N/Y 00h11h STORE_DEFAULT_ALL Sendbyte W W W W 0 N/Y —12h RESTORE_DEFAULT_ALL Sendbyte W W W W 0 N/Y —19h CAPABILITY Readbyte R R R R 1 N/N 20h/30h20h VOUT_MODE Readbyte R R R R 1 FIXED/N 40h25h VOUT_MARGIN_HIGH R/Wword R/W — — — 2 Y/Y 0000h26h VOUT_MARGIN_LOW R/Wword R/W — — — 2 Y/Y 0000h2Ah VOUT_SCALE_MONITOR R/Wword R/W R/W — — 2 Y/Y 7FFFh38h IOUT_CAL_GAIN R/Wword R/W R/W — — 2 Y/Y 0000h40h VOUT_OV_FAULT_LIMIT R/Wword R/W R/W — — 2 Y/Y 7FFFh42h VOUT_OV_WARN_LIMIT R/Wword R/W R/W — — 2 Y/Y 7FFFh43h VOUT_UV_WARN_LIMIT R/Wword R/W R/W — — 2 Y/Y 0000h44h VOUT_UV_FAULT_LIMIT R/Wword R/W R/W — — 2 Y/Y 0000h46h IOUT_OC_WARN_LIMIT R/Wword R/W R/W — — 2 Y/Y 7FFFh4Ah IOUT_OC_FAULT_LIMIT R/Wword R/W R/W — — 2 Y/Y 7FFFh4Fh OT_FAULT_LIMIT R/Wword — — R/W — 2 Y/Y 7FFFh51h OT_WARN_LIMIT R/Wword — — R/W — 2 Y/Y 7FFFh5Eh POWER_GOOD_ON R/Wword R/W R/W — — 2 Y/Y 0000h5Fh POWER_GOOD_OFF R/Wword R/W R/W — — 2 Y/Y 0000h60h TON_DELAY R/Wword R/W — — — 2 Y/Y 0000h62h TON_MAX_FAULT_LIMIT R/Wword R/W — — — 2 Y/Y FFFFh64h TOFF_DELAY R/Wword R/W — — — 2 Y/Y 0000h79h STATUS_WORD Readword R R R R 2 N/N 0000h7Ah STATUS_VOUT Readbyte R R — — 1 N/N 00h7Bh STATUS_IOUT Readbyte R R — — 1 N/N 00h7Dh STATUS_TEMPERATURE Readbyte — — R — 1 N/N 00h7Eh STATUS_CML Readbyte R R R R 1 N/N 00h



Table 3. PMBus Command Codes (continued)


PAGENO. OF BYTES


DEFAULT VALUE

(NOTE 2)0–11 12–15 16–20 255

(NOTE 1)

80h STATUS_MFR_SPECIFIC Readbyte R R — R 1 N/N 00h8Bh READ_VOUT Readword R R — — 2 N/N 0000h8Ch READ_IOUT Readword R R — — 2 N/N 0000h8Dh READ_TEMPERATURE_1 Readword — — R — 2 N/N 0000h98h PMBUS_REVISION Readbyte R R R R 1 FIXED/N 11h99h MFR_ID Readbyte R R R R 1 FIXED/N 4Dh9Ah MFR_MODEL Readbyte R R R R 1 FIXED/N 59h9Bh MFR_REVISION Readword R R R R 2 FIXED/N (Note3)9Ch MFR_LOCATION R/W64 R/W R/W R/W R/W 8 Y/Y (Note4)9Dh MFR_DATE R/W64 R/W R/W R/W R/W 8 Y/Y (Note4)9Eh MFR_SERIAL R/W64 R/W R/W R/W R/W 8 Y/Y (Note4)D1h MFR_MODE R/Wword R/W R/W R/W R/W 2 Y/Y 0020hD2h MFR_PSEN_CONFIG R/W32 R/W — — — 4 Y/Y (Note5)D4h MFR_VOUT_PEAK R/Wword R/W R/W — — 2 N/Y 0000hD5h MFR_IOUT_PEAK R/Wword R/W R/W — — 2 N/Y 0000hD6h MFR_TEMPERATURE_PEAK R/Wword — — R/W — 2 N/Y 8000hD7h MFR_VOUT_MIN R/Wword R/W R/W — — 2 N/Y 7FFFhD8h MFR_NV_LOG_CONFIG R/Wword R/W R/W R/W R/W 2 Y/Y 0000hD9h MFR_FAULT_RESPONSE R/W32 R/W R/W 4 Y/Y (Note5)DAh MFR_FAULT_RETRY R/Wword R/W R/W R/W R/W 2 Y/Y 0000hDCh MFR_NV_FAULT_LOG Read32 R R R R 255 Y/Y (Note6)DDh MFR_TIME_COUNT R/W32 R/W R/W R/W R/W 4 N/Y (Note5)DFh MFR_MARGIN_CONFIG R/Wword R/W — — — 2 Y/Y 0000h

E0h MFR_FW_SERIAL Rword — — — R 2 N/N <firmwarerevision>

E2h MFR_IOUT_AVG R/Wword R R — — 2 N/Y 0000hE4h MFR_CHANNEL_CONFIG R/Wword R/W R/W — — 2 Y/Y 0000hE6h MFR_TON_SEQ_MAX R/Wword R/W — — — 2 Y/Y 0000hE7h MFR_PWM_CONFIG(Note7) R/W32 R/W — — — 4 Y/Y (Note5)E8h MFR_SEQ_CONFIG R/W32 R/W — — — 4 Y/Y (Note5)



Note 1: Common commands are shaded; access through any page results in the same device response.Note 2: In the Flash Stored/Lockedcolumn,the“N”ontheleftindicatesthatthisparameterisnotstoredinflashmemorywhen

theSTORE_DEFAULT_ALLorMFR_STORE_ALLcommandisexecuted;thevalueshownintheDefault Value column is automatically loaded upon power-on reset or when the RSTpinisasserted.The“Y”ontheleftintheFlash Stored/Locked columnindicatesthatthecurrentlyloadedvalueinthisparameterisstoredinflashmemorywhentheSTORE_DEFAULT_ALLorMFR_STORE_ALLcommandisexecutedandisautomaticallyloadeduponpower-onresetorwhentheRSTpinisasserted; the value shown in the Default Valuecolumnisthevaluewhenshippedfromthefactory.“FIXED”intheFlash Stored column means that the value is fixed at the factory and cannot be changed. The value shown in the Default Value column is automatically loaded upon power-on reset or when the RSTpinisasserted.Theright-sideY/Nindicatesthatwhenthedeviceislocked,onlythecommandslistedwith“N”canbeaccessed.AllothercommandsareignoredifwrittenandreturnFFhifread.OnlythePAGE,CLEAR_FAULTS,OPERATION,andMFR_SERIALcommandscanbewrittento.Thedeviceunlocksiftheupper4bytesofMFR_SERIALmatchthedatawrittentothedevice.

Note 3: The factory-set value is dependent on the device hardware and firmware revision.Note 4: Thefactory-setdefaultvalueforthis8-byteblockis3130313031303130h.Note 5: Thefactory-setdefaultvalueforthis4-byteblockis00000040h.Note 6: Thefactory-setdefaultvalueforthecompleteblockoftheMFR_NV_FAULT_LOGisFFh.Note 7: MFR_PWM_CONFIGisonlyavailableforPAGES0–7.

PMBus/SMBus Address SelectOndevicepower-up, thedevicesamples theADDRpinto determine the PMBus/SMBus serial-port address.The combination of the components shown in Figure 1 determinestheserial-portaddress(alsoseeTable 4).

SMBus/PMBus OperationThe device implements the PMBus command structureusing theSMBus format.The structureof thedata flowbetween the host and the slave is shown below for several different types of transactions. All transactions begin with a host sending a command code that is immediatelyprecededwitha7-bitslaveaddress(R/W=0).DataissentMSBfirst.

Table 3. PMBus Command Codes (continued)

Figure 1. PMBus/SMBus Address Select


PAGENO. OF BYTES


DEFAULT VALUE

(NOTE 2)0–11 12–15 16–20 255

(NOTE 1)

EEh MFR_STORE_ALL Writebyte W W W W 1 N/Y —EFh MFR_RESTORE_ALL Writebyte W W W W 1 N/Y —F0h MFR_TEMP_SENSOR_CONFIG R/Wword — — R/W — 2 Y/Y 0000hFCh MFR_STORE_SINGLE R/Wword R/W R/W R/W R/W 2 N/Y 0000hFEh MFR_CRC R/Wword R/W R/W R/W R/W 2 N/Y FFFFh

MSDAMSCL

MAX34451

ADDR

R1

R2C2

R3 R4



SMBus/PMBus Operation Examples

Table 4. PMBus/SMBus Serial-Port Address

Note: The device also responds to a slave address of 34h (this is the factory programming address); the device should not share the same I2C bus with other devices that use this slave address. The letter "x" in the Slave Address column indicates the R/W bit location.

R1 R2 R3 R4 C2 SLAVE ADDRESS— 220kΩ — — — 1110100x(E8h)

220kΩ — — — — 1110101x(EAh)220kΩ — — — 100nF 0010010x(24h)22kΩ — — — 100nF 0010011x(26h)

— — 0kΩ — — 1001100x(98h)— — 220kΩ — — 1001101x(9Ah)— — — 0kΩ — 1011000x(B0h)— — — 220kΩ — 1011001x(B2h)— 0kΩ — — — 1001110x(9Ch)

KEY:S=STARTSr=REPEATEDSTARTP=STOPW=WRITEBIT(0)R=READBIT(1)A=ACKNOWLEDGE(0)NA=NOTACKNOWLEDGE(1)SHADEDBLOCK=SLAVETRANSACTION

READ WORD FORMAT1 7 1 1 8 1 1 7 1 1 8 1 8 1 1

S SLAVEADDRESS W A COMMAND

CODE A Sr SLAVEADDRESS R A DATABYTE

LOW A DATABYTEHIGH NA P

READ BYTE FORMAT1 7 1 1 8 1 1 7 1 1 8 1 1


CODE A Sr SLAVEADDRESS R A DATABYTE NA P

WRITE WORD FORMAT1 7 1 1 8 1 8 1 8 1 1


CODE A DATABYTELOW A DATABYTE

HIGH A P

WRITE BYTE FORMAT1 7 1 1 8 1 8 1 1


CODE A DATA BYTE A P

SEND BYTE FORMAT1 7 1 1 8 1 1


CODE A P



Group CommandThedevicesupportsthegroupcommand.Withthegroupcommand, a host can write different data to multiple

devices on the same serial bus with one long continuous data stream. All the devices addressed during this trans-actionwaitforthehosttoissueaSTOPbeforebeginningto respond to the command.

Group Command Write Format

AddressingThe device responds to receiving its fixed slave address by asserting an acknowledge (ACK) on the bus. Thedevice does not respond to a general call address; it only responds when it receives its fixed slave address orthealertresponseaddress.SeetheALERT and Alert Response Address (ARA) section for more details.

ALERT and Alert Response Address (ARA)If the ALERT output is enabled (ALERT bit = 1 inMFR_MODE) when a fault occurs, the device assertsthe ALERT signal and then waits for the host to send an ARA, as shown in the Alert Response Address (ARA) Byte Format section.

Alert Response Address (ARA) Byte Format

When the ARA is received and the device is assertingALERT,thedeviceACKsitandthenattemptstoplaceitsfixed slave address on the bus by arbitrating the bus, since anotherdevicecouldalsotrytorespondtotheARA.Therules of arbitration state that the lowest address device wins. If the device wins the arbitration, it deasserts ALERT. If the device loses arbitration, it keeps ALERT asserted and waitsforthehosttoonceagainsendtheARA.

SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 11 7 1 1 8 1 8 1 8 1



HIGH A U U U

SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 21 7 1 1 8 1 8 1

Sr SLAVEADDRESS W A COMMAND

CODE A DATABYTE A U U U

SLAVE ADDRESS AND SEND BYTE FOR DEVICE 31 7 1 1 8 1


CODE A U U U

U U U

SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N1 7 1 1 8 1 8 1 8 1 1



HIGH A P

KEY:S=STARTSr=REPEATEDSTARTP=STOPW=WRITEBIT(0)R=READBIT(1)A=ACKNOWLEDGE(0)NA=NOTACKNOWLEDGE(1)SHADEDBLOCK=SLAVETRANSACTION

1 7 1 1 8 1 1

S ARA0001100 R A DEVICESLAVE

ADDRESSWITHLSB=0 NA P



Host Sends or Reads Too Few BitsIf, for any reason, the host does not complete writing a full byteorreadingafullbytefromthedevicebeforeaSTARTorSTOPisreceived,thedevicedoesthefollowing:1) Ignoresthecommand.2) SetstheCMLbitinSTATUS_WORD.3) SetstheDATA_FAULTbitinSTATUS_CML.4) NotifiesthehostthroughALERTassertion(ifenabled).

Host Sends or Reads Too Few BytesForeachsupportedcommand,thedeviceexpectsafixednumber of bytes to be written to or read from the device. If, for any reason, less than the expected number of bytes are written to or read from the device, the device completely ignores the command and takes no action.

Host Sends Too Many Bytes or BitsForeachsupportedcommand,thedeviceexpectsafixednumber of bytes to be written to the device. If for any reason, more than the expected number of bytes or bits is writtentothedevice,thedevicedoesthefollowing:1) Ignoresthecommand.2) SetstheCMLbitinSTATUS_WORD.3) SetstheDATA_FAULTbitinSTATUS_CML.4) NotifiesthehostthroughALERTassertion(ifenabled).

Host Reads Too Many Bytes or BitsForeachsupportedcommand,thedeviceexpectsafixednumber of bytes to be read from the device. If, for any reason, more than the expected number of bytes or bits is readfromthedevice,thedevicedoesthefollowing:1) Sends all ones (FFh) as long as the host keeps

acknowledging.2) SetstheCMLbitinSTATUS_WORD.3) SetstheDATA_FAULTbitinSTATUS_CML.4) NotifiesthehostthroughALERTassertion(ifenabled).

Host Sends Improperly Set Read Bit in the Slave Address ByteIfthedevicereceivestheR/W bit in the slave address set to a one immediately preceding the command code, the devicedoesthefollowing(thisdoesnotapplytotheARA):1) ACKstheaddressbyte.2) Sends all ones (FFh) as long as the host keeps

acknowledging.

3) SetstheCMLbitinSTATUS_WORD.4) SetstheDATA_FAULTbitinSTATUS_CML.5) NotifiesthehostthroughALERTassertion(ifenabled).

Unsupported Command Code Received/Host Writes to a Read-Only CommandIf the host sends the device a command code that it does not support, or if the host sends a command code that isnotsupportedbythecurrentPAGEsetting,thedevicedoesthefollowing:1) Ignoresthecommand.2) SetstheCMLbitinSTATUS_WORD.3) SetstheCOMM_FAULTbitinSTATUS_CML.4) NotifiesthehostthroughALERTassertion(ifenabled).

Invalid Data ReceivedThedevicechecksthePAGE,OPERATION,andWRITE_PROTECT command codes for valid data. If the hostwrites a data value that is invalid, the device does the following:1) Ignoresthecommand.2) SetstheCMLbitinSTATUS_WORD.3) SetstheDATA_FAULTbitinSTATUS_CML.4) NotifiesthehostthroughALERTassertion(ifenabled).

Host Reads from a Write-Only CommandWhen a read request is issued to a write-only command (CLEAR_FAULTS, STORE_DEFAULT_ALL, RESTORE_DEFAULT_ALL, MFR_STORE_ALL, MFR_RESTORE_ALL,OPERATIONwithPAGE=255),thedevicedoesthefollowing:1) ACKstheaddressbyte.2) Ignoresthecommand.3) Sends all ones (FFh) as long as the host keeps

acknowledging.4) SetstheCMLbitinSTATUS_WORD.5) SetstheDATA_FAULTbitinSTATUS_CML.6) NotifiesthehostthroughALERTassertion(ifenabled).

SMBus TimeoutIf, during an active SMBus communication sequence,the SCL signal is held low for greater than the timeoutduration (nominally 27ms), the device terminates thesequence and resets the serial bus. It takes no other action.Nostatusbitsareset.



PMBus OperationFrom a software perspective, the device appears as aPMBus device capable of executing a subset of PMBuscommands.Inthisdatasheet,thetermSMBusisusedtorefer to the electrical characteristics of the PMBus com-munication using the SMBus physical layer. The termPMBusisusedtorefertothePMBuscommandprotocol.ThedeviceemploysanumberofstandardSMBusproto-cols(e.g.,WriteWord,ReadWord,WriteByte,ReadByte,SendByte, etc.) to programoutput voltageandwarning/fault thresholds, read monitored data, and provide access to all manufacturer-specific commands.The device supports the group command. The group command is used to send commands to more than one PMBus device. It is not required that all the devicesreceive the same command. However, no more than one command can be sent to any one device in one group command packet. The group command must not be used with commands that require receiving devices to respond withdata,suchastheSTATUS_WORDcommand.Whenthe device receives a command through this protocol, it immediately begins execution of the received command afterdetectingtheSTOPcondition.ThedevicesupportsthePAGEcommandanduses it toselectwhich individual channel toaccess.Whenadataword is transmitted, the lower order byte is sent first and the higher order byte is sent last.Within any byte,themost-significantbit (MSB) issent firstand the least-significantbit(LSB)issentlast.

PMBus Protocol SupportThe device supports a subset of the commands defined in the PMBus Power System Management ProtocolSpecificationPartII-CommandLanguageRevision1.1.

FordetailedspecificationsandthecompletelistofPMBuscommands, refer to Part II of the PMBus specificationavailable at www.PMBus.org. The supported PMBuscommands and the corresponding device behavior are described in this document. All data values are represent-edinDIRECTformat,unlessotherwisestated.Wheneverthe PMBus specification refers to the PMBus device, itis referring to the device operating in conjunction with a powersupply.Whilethecommandcancallforturningonoroff thePMBusdevice, thedevicealways remainsonto continue communicatingwith thePMBusmaster andtransfers the command to the power supply accordingly.

Data FormatVoltage data for commanding or reading the output voltage or related parameters (such as the overvoltagethreshold) are presented in DIRECT format. DIRECTformat data is a 2-byte, two’s complement binary value. DIRECTformatdatacanbeusedwithanycommandthatsendsor readsaparametricvalue.TheDIRECT formatuses an equation and defined coefficients to calculate the desired values. Table 5 lists coefficients used by the device.

Interpreting Received DIRECT Format ValuesThe host system uses the following equation to convert thevaluereceivedfromthePMBusdevice—inthiscasethe MAX34451—into a reading of volts, degrees Celsius, orotherunitsasappropriate:

X=(1/m)x(Yx10–R-b)where X is the calculated real-world value in the appropriateunits(V,°C,etc.);mistheslopecoefficient;Y is the2-byte, two’scomplement integerreceivedfromthePMBusdevice;bistheoffset;andRistheexponent.



http://www.PMBus.org

Note: Toreliablyprocessfault-retryduringsimultaneousfaulteventsonmultiplechannels,itisrecommendedtosetMFR_FAULT_RETRY≥ 1ms.

Sending a DIRECT Format ValueTo send a value, the host must use the following equation tosolveforY:

Y=(mX+b)x10R

where Y is the 2-byte, two’s complement integer to besent to the unit; m is the slope coefficient; X is the real-world value, in units such as volts, to be converted for transmission;bistheoffset;andRistheexponent.The following example demonstrates how the host can send and retrieve values from the device. Table 6 lists the coefficients used in the following parameters.

If a host wants to set the device to change the power-supplyoutputvoltageto3.465V(or3465mV),the correspondingVOUT_MARGIN_HIGHvalueis:

Y=(1x3465+0)x100=3465(decimal) =0D89h(hex)

Table 5. PMBus Command Code Coefficients

Table 6. Coefficients for DIRECT Format Value

PARAMETER COMMANDS UNITS RESOLUTION MAXIMUM m b R

Voltage

VOUT_MARGIN_HIGHVOUT_MARGIN_LOWVOUT_OV_FAULT_LIMITVOUT_OV_WARN_LIMITVOUT_UV_WARN_LIMITVOUT_UV_FAULT_LIMITPOWER_GOOD_ONPOWER_GOOD_OFFREAD_VOUTMFR_VOUT_PEAKMFR_VOUT_MIN

mV 1 32767 1 0 0

VoltageScaling VOUT_SCALE_MONITOR — 1/32767 1 32767 0 0

Current

IOUT_OC_FAULT_LIMITIOUT_OC_WARN_LIMITREAD_IOUTMFR_IOUT_PEAKMFR_IOUT_AVG

A 0.01 327.67 1 0 2

CurrentScaling IOUT_CAL_GAIN mΩ 0.1 3276.7 1 0 1

Temperature

OT_FAULT_LIMITOT_WARN_LIMITREAD_TEMPERATURE_1MFR_TEMPERATURE_PEAK

°C 0.01 327.67 1 0 2

Timing

TON_DELAYTON_MAX_FAULT_LIMITTOFF_DELAYMFR_FAULT_RETRYMFR_TON_SEQ_MAX

ms 0.2 6553.4 5 0 0

COMMAND CODE COMMAND NAME m b R

25h VOUT_MARGIN_HIGH 1 0 08Bh READ_VOUT 1 0 0



Conversely, if the host received a value of 0D89hon aREAD_VOUTcommand,thisisequivalentto:X=(1/1)x(0D89hx10-(-0)-0)=3465mV=3.465V

Power supplies and power converters generally haveno way of knowing how their outputs are connected to ground. Within the power supply, all output voltagesare most commonly treated as positive. Accordingly, all output voltages and output-voltage-related parameters of PMBusdevicesarecommandedandreportedaspositivevalues. It is up to the system to know that a particular output is negative if that is of interest to the system. All output-voltage-related commands use 2 data bytes.

Fault Management and ReportingFor reporting faults/warnings to the host on a real-timebasis, the device asserts the open-drain ALERT pin (ifenabled inMFR_MODE) and sets the appropriate bit inthe various status registers. On recognition of the ALERT assertion, the host or system manager is expected to poll the I2C bus to determine the device asserting ALERT. Thehostsends theSMBusARA(0001100).ThedeviceACKs theSMBusARA, transmits its slave address, and deasserts ALERT. The system controller then communicateswithPMBuscommandstoretrievethefault/warning status information from the device.See the individual command sections for more details.Faults and warnings that are latched in the status registers are cleared when any one of the following conditionsoccur: ACLEAR_FAULTScommandisreceived. TheRST pin is toggled or a soft-reset is issued.

Bias power to the device is removed and then reapplied.

One or more latched-off power supplies are only restarted whenoneofthefollowingoccurs: OPERATIONcommandsarereceivedthatturnoffand

turnonthepowersupplies,ortheCONTROLnpinsaretoggled to turn off and then turn on the power supplies.

TheRST pin is toggled or a soft-reset is issued. Bias power to the device is removed and then

reapplied.The device responds to fault conditions according to the configuration of the MFR_FAULT_RESPONSE command. This command determines how the device should respond to each particular fault and whether it should assert one or more of the FAULTn pins when a fault occurs.TheMFR_FAULT_RESPONSEcommandalsodetermineswhether a channel should power up if a fault is present. With the RESPONSE bits in MFR_FAULT_RESPONSE,each channel can be independently configured to either respond or not respond to each possible fault. Beforeany power-supply channel is enabled, or the FAULTn outputs deasserted, the device checks for overvoltage, overcurrent, and temperature faults (but not for undervoltage) if the channel is configured for a faultresponsetoeitherlatchoff(RESPONSE[1:0]=01)orretry(RESPONSE[1:0]=10) in theMFR_FAULT_RESPONSEcommand. Only after the faults clear is the channel allowed toturnon.SeeTable 7 for fault-monitoring states.



Table 7. Fault-Monitoring States

Note: Device response to faults is determined by the configuration of MFR_FAULT_RESPONSE.

FAULT REQUIRED DEVICE CONFIGURATIONFOR ACTIVE MONITORING WHEN MONITORED

Overvoltage • Voltage monitoring enabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG) Continuous monitoring.

Undervoltage/ PowerGood

• Voltage monitoring enabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG)

• IfSELECT[5:0]=10h(monitorandsequencemode),stopsmonitoringwhenPSENisdisabled.PowerGoodstartsmonitoringwhenPSENisenabledandUndervoltagemonitoringstartswhenvoltageexceedsthePOWER_GOOD_ONlevel.

• IfSELECT[5:0]=20h(monitoronlymode),starts monitoring when the voltage exceeds thePOWER_GOOD_ONlevel.

Overcurrent • Current monitoring enabled• (SELECT[5:0]=22hinMFR_CHANNEL_CONFIG) Continuous monitoring.

Power-UpTime • Sequencingenabled• (SELECT[5:0]=10hinMFR_CHANNEL_CONFIG) Monitored only during power-on sequence.

Overtemperature • Temperature sensor enabled• (ENABLE=1inMFR_TEMP_SENSOR_CONFIG) Continuous monitoring.



Password ProtectionThe device can be password protected by using the LOCK bit in the MFR_MODE command. Once thedeviceis locked,onlycertainPMBuscommandscanbeaccessedwiththeserialport.SeeTable 3 for a complete listofPMBuscommands.Commandsthathavepasswordprotectionreturnallones(FFh),with thepropernumberof data bytes, when read. When the device is locked,only the PAGE, OPERATION, CLEAR_FAULTS, andMFR_SERIALcommandscanbewritten;allotherwritten commands are ignored. When MFR_SERIAL is writtenand the upper 4 bytes match the internally flash-stored value, the device unlocks and remains unlocked until the LOCK bit in MFR_MODE is activated once again. TheLOCK status bit in STATUS_MFR_SPECIFIC is alwaysavailable to indicate whether the device is locked or unlocked.

Power-Supply SequencingSequencing control for each of the 12 power-supply channels on the device is configured using the MFR_SEQ_CONFIGandON_OFF_CONFIGcommands.

See the descriptions of these commands for details onthe exact device configuration required.Power suppliescanbepoweredupanddowninanyorder(evenacross multiple devices). See the command descriptions andFigure2 for specifics on sequencing control.

Dual-Loop SequencingThe device contains two independent sequencing groups, SEQUENCE0 and SEQUENCE1. Both groups do notneed to be used, but every channel is assigned to one of the twogroupswith theSEQ_SELECTbit in theMFR_SEQ_CONFIG command. The two sequencing groupsoperateindependently.SEQUENCE0isalwaysassociatedwithCONTROL0andSEQUENCE1isalwaysassociatedwithCONTROL1.Thetwosequencinggroupscanalsobeindependently controlled with the OPERATION command.With the ON_OFF_CONFIG command, the device isconfigured to respond to the CONTROLn pins or theOPERATIONcommand(orboth).WhentheOPERATIONcommandissenttothedevice(whenthePAGEissetto255),bothsequencegroupsarecontrolled,asshowninTable8.

Figure 2. Sequence Control Logic

MFR_TON_SEQ_MAX

SEQ MATCH

SELECTSELECTON_OFF_CONFIG

MFR_SEQ_CONFIGBITS 31:16 BIT 0 BITS 11:8 BITS 5:4

BIT 14BIT 26BIT 25BIT 24

SEQUENCE0

SEQUENCE1

OR

AND

AND

OR

J

K

ON

OFF

STOPSTART

PSEN0–PSEN11

POWER–SUPPLYENABLES

SEQ(OPTIONAL FUNCTION

OF PSEN11)

POWER-ONOPERATION COMMAND

CONTROL0CONTROL1

PG0/GPI0–PG15/GPI15

FAULT0

FAULT1(OPTIONAL FUNCTION

OF PWM7)

FAULT2(OPTIONAL FUNCTION

OF PSEN10)

16

16

GLOBAL/LOCAL

SELECTOR

AND

AND

AND

GLOBAL

LOCAL

MFR_FAULT_RESPONSE

LOCAL0–LOCAL11

NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS. SHADED BLOCKS ARE PMBus COMMANDS.



Power-On SequencingTheactivationofallpower-supplychannels(evenacrossmultiple devices) is initiated from a common START signalthatcaneitherbetheCONTROL0orCONTROL1pin, or the OPERATION command. Each power-supplychannel on the device can be sequenced on by one of the followingmethods: Powerisappliedtothedevice. TheCONTROL0pingoesactive. TheCONTROL1pingoesactive. TheOPERATIONcommandisreceived. ThelogiccombinationofpowergoodsandGPIisvalid. TheSEQ pin signal is matched.Each enabled PSENn output goes active (either activehigh or active low, as defined inMFR_PSEN_CONFIG)after the associated delay time programmed in TON_DELAY. The power supplies can be sequenced on inany order. Each channel can be sequenced on witheither time-based or event-based conditions. The output voltage of each power supply is monitored to ensure that the supply crosses the power-good-on level (as con-figured in the POWER_GOOD_ON command) within aprogrammabletimelimit,asconfiguredintheTON_MAX_FAULT_LIMIT command. This power-up time limit canbe disabled by configuring TON_MAX_FAULT_LIMIT to0000h.Forchannelsusingevent-basedsequencing,theMFR_TON_SEQ_MAX command determines the maxi-mumtime limit for thesequence-onevent tooccur.LiketheTON_MAX_FAULT_LIMIT, this limit can be disabledbyconfiguringMFR_TON_SEQ_MAXto0000h.Thereisaone-to-onecorrespondencebetweentheRSninputsandthePSENnoutputs.Forexample,RS6monitorsthepowersupply controlled byPSEN6.All power-on sequencing isgatedbydetectedfaults.Beforeanypower-supplychannelisenabled(ortheFAULTnoutputdeasserted)thedevicechecks for overvoltage, overcurrent, and temperature faultsthatareenabled(butnotforundervoltagesincethesupplyisoff).

Power-Off SequencingThe order in which the supplies are disabled is deter-minedwiththeTOFF_DELAYconfiguration.Alternatively,

all the power supplies can be switched off immediately, asconfiguredintheON_OFF_CONFIGcommandorwiththeOPERATIONcommand.As configured with the ON_OFF_CONFIG command,either the CONTROL0 or CONTROL1 pin or theOPERATION command is the master off switch.WheneithertheCONTROL0orCONTROL1pingoesinactive,or theOPERATIONoffcommand is received (oroneofthe enabled FAULTnpinsasserted), thepowersuppliesaresequencedoff.Neither thepower-good(PG)orGPIlogic combinations, nor the SEQ pin, can be used to turn off the power supplies.

Sequencing ExampleAs an example, Figure 3 details a simple sequencing scheme consisting of four power supplies using a mixture of time-based and event-based sequencing. Channels 0and 2 use time-based sequencing and channels 1 and 5 useevent-basedsequencing.WheneithertheCONTROL0or CONTROL1 pin goes active, or the OPERATION command is received (as defined by the ON_OFF_CONFIGcommand),PSEN0isassertedafterthedelaytime configured in TON_DELAY. RS0 is monitored to ensurethat the PSEN0 supply crosses the power-good-onlevel (as configured in POWER_GOOD_ON) within a programmable time limit (as configured in TON_MAX_FAULT_LIMIT). PSEN2 operates in a similar fashion asPSEN0,butwithadifferentTON_DELAYandadifferentTON_MAX_FAULT_LIMIT.Sincethepower-upofchannels0 and 2 are based solely on their TON_DELAY values,these channels are time-based.When RS2 crosses its power-good-on level, PSEN5 isasserted after its configuredTON_DELAYand similarly,PSEN1 asserts when RS5 crosses its power-good-onlevel.Sincethepower-upofchannels5and1arebasedon the power-good states of other channels, these channels are event-based. The MFR_TON_SEQ_MAXcommand can be used to ensure that these events occur and the power-up sequence does not hang waiting for an eventtotranspire.WhenRS1crossesitspower-good-onlevel, it has been configured to generate a SEQ pin signal to communicate to another device to turn on one or more of its power supplies.

Table 8. OPERATION Command Sequence Control Options

GROUPOPERATION COMMAND (PAGE = 255)

ON SOFT-OFF IMMEDIATE OFFSEQUENCE0 80hor81h 40hor41h 00hor01hSEQUENCE1 80hor82h 40hor42h 00hor02h



Multiple Device ConnectionsMultiple MAX34451 devices can be connected together to increase the system channel count. Figure4 details the recommended connection scheme.All the paralleled devices share the sameCONTROLn,FAULTn, SEQ,andSMBussignals.Thedevicesalluseacommonsignal(eithertheCONTROL0orCONTROL1pin,or theOPERATIONcommand) toenable/disableallthe power supplies. Any of the monitored power supplies can be configured with the MFR_FAULT_RESPONSEcommand to activate one or more of the FAULTn signals and shut down all the other supplies enabled to respond

to one or more of the FAULTn signals. The FAULT0 signal is always available, whereas FAULT1 and FAULT2 are optionalsignals.Whentheyareenabled,thePWM7andPSEN10outputs (respectively)aredisabled.Theuseofmultiple fault signals allows more flexibility in controlling which power supplies need to shut down during a fault.USER NOTE: All devices must be configured with the same ON_

OFF_CONFIGconfiguration. All devices must be powered up and reset at the same

time.

Figure 3. Sequencing Example

POWER_GOOD_ON

TON_MAX_FAULT_LIMIT

TON_DELAYPOWER_GOOD_ON

TON_MAX_FAULT_LIMIT

TON_DELAY

POWER_GOOD_ON

TON_MAX_FAULT_LIMIT

TON_DELAY

POWER_GOOD_ON

TON_MAX_FAULT_LIMIT

TOFF_DELAY

TOFF_DELAY

TOFF_DELAY

TOFF_DELAY

NOTES 1 AND 2

TON_DELAY

POWER-DOWNPOWER-UP

CONTROL0/1 PINOR OPERATION COMMAND

PSEN0

RS0

RS2

RS5

RS1

SEQ

PSEN2

PSEN5

PSEN1

NOTES: 1. ALTERNATE POWER-DOWN SEQUENCING OPERATION IS TO SHUT OFF ALL SUPPLIES IMMEDIATELY. 2. THE FAULTn PIN BEING ASSERTED LOW CAN ALSO CAUSE A POWER-DOWN SEQUENCE TO OCCUR.



SEQ Pin OperationThe SEQpinisanotheroptionalsignal.Whenthisfunctionis enabled, it allows multiple devices to coordinate event-based sequencing. With the MFR_CHANNEL_CONFIGcommand, any channel can be configured to generate one of 15 signatures. When the channel crosses its power-good-on level, it generates the needed SEQ signature if so enabled. With the MFR_SEQ_CONFIG command,any of the sequencing channels (PAGES 0–11) can be configured to wait for a match on the SEQ pin before assert-ingthePSENnoutput.Toensurethatavalid SEQ signal is received when it should be, the maximum allowable time is configuredintotheMFR_TON_SEQ_MAXcommand.USER NOTE: Only one channel should be configured to generate

any one particular SEQ signature. If two channels generate the same signature, they might reach their power-good-on levels at different times and corrupt the SEQ signal.

Allow more than 15ms between consecutive SEQ signatures.

System Watchdog TimerThe device uses an internal watchdog timer. This timer is internally reset every 5ms. In the event the device is locked up, and the watchdog reset does not occur after 210ms, thedevice isautomatically reset.After the resetoccurs, the device reloads all configuration values that were stored to flash and begins normal operation. After thereset,thedevicealsodoesthefollowing:1) SetstheMFRbitinSTATUS_WORD.2) Sets the WATCHDOG_INT bit in STATUS_MFR_

SPECIFIC(forPAGE255).3) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

CRC Memory CheckUponreset,thedevicerunsaninternalalgorithmtocheckthe integrity of the key internal nonvolatile memory. If theCRCcheck fails, thedevicedoesnotpowerupandremains in a null state with all pins high impedance but asserts the FAULT0 output.

Figure 4. Multiple MAX34451 Hardware Connections

SCL/SDA (UNIQUE ADDRESS)

CONTROL0

MAX34451

CONTROL1HARDWARE

CONTROL

PMBusCONTROL

FAULT0FAULT1 (OPTIONAL)FAULT2 (OPTIONAL)

SEQ (OPTIONAL)


CONTROL0

MAX34451

CONTROL1


SEQ (OPTIONAL)


CONTROL0

MAX34451

CONTROL1


SEQ (OPTIONAL)



PMBus CommandsA summary of thePMBus commands supported by thedevice are described in the following sections.

PAGE (00h)The device can monitor up to 16 voltages or currents, sequence up to 12 power supplies, and margin up to 12 power supplies. The device can monitor up to five temperature sensors, one internal local tempera-ture sensor, plus four external remote temperature sensors (DS75LV). All the monitoring and control is accomplishedusingonePMBus(I2C)address.Send the

PAGEcommandwithdata0–20(decimal)toselectwhichpower supply or temperature sensor is affected by all the following PMBus commands. Not all commands are supported within each page. If an unsupported command is received, the CML status bit is set. Some commandsare common, which means that any selected page has the same effect on and the same response from the device. SeeTable 9forPAGEcommands.Set the PAGE to 255 when the following PMBus commands should apply to all pages at the same time. Thereareonlyafewcommands(OPERATION,CLEAR_FAULTS)wherethisfunctionhasarealapplication.

Table 9. PAGE (00h) Commands

*PAGES 0–11 can also be used to configure GPI and GPO operation.

PAGE* ASSOCIATED CONTROL0 PowersupplymonitoredbyRS0,controlledbyPSEN0,andmarginedwithPWM0.1 PowersupplymonitoredbyRS1,controlledbyPSEN1,andmarginedwithPWM1.2 PowersupplymonitoredbyRS2,controlledbyPSEN2,andmarginedwithPWM2.3 PowersupplymonitoredbyRS3,controlledbyPSEN3,andmarginedwithPWM3.4 PowersupplymonitoredbyRS4,controlledbyPSEN4,andmarginedwithPWM4.5 PowersupplymonitoredbyRS5,controlledbyPSEN5,andmarginedwithPWM5.6 PowersupplymonitoredbyRS6,controlledbyPSEN6,andmarginedwithPWM6.7 PowersupplymonitoredbyRS7,controlledbyPSEN7,andmarginedwithPWM7.

8 PowersupplymonitoredbyRS8,controlledbyPSEN8,andoptionallymarginedbyOUT0ofexternal DS4424atI2CaddressA0h.




12 ADCchannel12(monitorsvoltageorcurrent)orGPI.13 ADCchannel13(monitorsvoltageorcurrent)orGPI.14 ADCchannel14(monitorsvoltageorcurrent)orGPI.15 ADCchannel15(monitorsvoltageorcurrent)orGPI.16 Internal temperature sensor.17 ExternalDS75LVtemperaturesensorwithI2Caddress90h.18 ExternalDS75LVtemperaturesensorwithI2C address 92h.19 ExternalDS75LVtemperaturesensorwithI2C address 94h.20 ExternalDS75LVtemperaturesensorwithI2C address 96h.

21–254 Reserved.255 Applies to all pages.



OPERATION (01h)The OPERATION command is used to turn the powersupply on and off in conjunction with the CONTROLninput pin. The OPERATION command is also used tocause the power supply to set the output voltage to the upper or lower margin voltages. The power supply stays in the commanded operating mode until a subsequent OPERATION command or a change in the state ofthe CONTROLn pin (if enabled) instructs the power supplytochangetoanotherstate.ThevalidOPERATIONcommand byte values are shown in Table 10. The OPERATIONcommandcontrolshowthedevicerespondswhen commanded to change the output. When the commandbyte is00h, thedevice immediately turns thepower supply off and ignores any programmed turn-off delay.Whenthecommandbyteissetto40h,41h,or42hthe device powers down, according to the programmed turn-off delay. In Table 10, Table 11, and Table 12, “acton any fault”means that if anywarning or fault on theselected power supply is detected when the output is margined, the device treats this as a warning or fault and respondsasprogrammed. “Ignoreall faults”means that

all warnings and faults on the selected power supply are ignored. Any command value not shown in these tables is an invalid command. If the device receives a data byte that is not listed in these tables, then it treats this as invalid data, declaresadata fault (setsCMLbit andasserts ALERT),andrespondsasdescribedintheFault Management and Reporting section.In most cases, for power-on and power-off control, the OPERATIONcommandshouldbesentwhen thePAGEissetto255.IfthePAGEissetto0–11,theOPERATIONcommand is only applied to the power supply on that page and the power supply is turned on and off using the associated TON_DELAY and TOFF_DELAY settings without any regard to the other supplies.Forindividualchannel-marginingcontrol,theOPERATIONcommandcanbeusedwiththePAGEsetto0–11.Whenthe PAGE is set to 255, the OPERATION margining commands affect all channels.TheOPERATIONcommandforthedevicecontainsafewspecial values that are not part of thePMBus standardtoallowthedevicetoofferindependentcontrol.Seetheshaded values in Table 11.

Table 10. OPERATION (01h) Command Byte with PAGE = 0–11 (When Bit 3 of ON_OFF_CONFIG = 1)

Note: All enabled channels must exceed POWER_GOOD_ON for margining to begin.

COMMAND BYTE POWER SUPPLY ON/OFF MARGIN STATE

00h Immediateoff(nosequencing) —

40h Soft-off(withsequencing) —

80h On Marginoff

94h On Marginlow(ignoreallfaults)

98h On Marginlow(actonanyfault)

A4h On Marginhigh(ignoreallfaults)

A8h On Marginhigh(actonanyfault)



Table 11. OPERATION (01h) Command Byte with PAGE = 255 (When Bit 3 of ON_OFF_CONFIG = 1)

Note: Special device OPERATION commands are shaded; when the OPERATION command is read, the device always responds with the standard command; all enabled channels must exceed POWER_GOOD_ON for margining to begin.

Table 12. OPERATION (01h) Command Byte (When Bit 3 of ON_OFF_CONFIG = 0)

Note: The device only takes action if the supply is enabled; all enabled channels must exceed POWER_GOOD_ON for margining to begin; if PAGE is set to 255, both SEQUENCE0 and SEQUENCE1 are affected.

COMMAND BYTE POWER SUPPLY ON/OFF SEQUENCE AFFECTED MARGIN STATE

00hImmediateoff (nosequencing)

SEQUENCE0andSEQUENCE1

n/a

01h SEQUENCE0only02h SEQUENCE1only

40hSoft-off

(withsequencing)


41h SEQUENCE0only42h SEQUENCE1only

80hOn


Marginoff81h SEQUENCE0only82h SEQUENCE1only94h On


Marginlow(ignoreallfaults)98h On Marginlow(actonanyfault)A4h On Marginhigh(ignoreallfaults)A8h On Marginhigh(actonanyfault)

COMMAND BYTE POWER SUPPLYON/OFF MARGIN STATE

00h

Commandhasnoeffect

n/a40h80h Marginoff94h Marginlow(ignoreallfaults)98h Marginlow(actonanyfault)A4h Marginhigh(ignoreallfaults)A8h Marginhigh(actonanyfault)



ON_OFF_CONFIG (02h)TheON_OFF_CONFIGcommandconfiguresthecombina-tion of the CONTROLn input and PMBus OPERATIONcommands needed to turn the power supply on and off. This indicates how the power supply is command-

ed when power is applied. The ON_OFF_CONFIG message content is described in Table 13. The host should not modify ON_OFF_CONFIG while the power suppliesare active. The configuration of the ON_OFF_CONFIGcommand applies to bothCONTROL0 andCONTROL1. SeeFigure5.

Table 13. ON_OFF_CONFIG (02h) Command Byte

*Unless bit 5 is set (if both bits 3:2 are set), both the CONTROL0 or CONTROL1 pin and the OPERATION command are required to turn the supplies on, and either can turn the supplies off.

BIT PURPOSE VALUE MEANING

7:6 Reserved. n/a Alwaysreturns000.

5 OPERATIONcommandandCONTROLnpinand/orselect.

0 OPERATIONcommandisANDedwithCONTROLnpinifbothareenabled.

1 OPERATIONcommandisORedwithCONTROLnpinifbothareenabled.

4Turn on supplies when bias is presentorusetheCONTROLnpin/OPERATIONcommand.

0 Turnsonthesupplies(withsequencingifsoconfigured)assoonasbiasissuppliedtothedevice,regardlessoftheCONTROLnpin.

1 UsesCONTROLnpins(ifenabled)and/orOPERATIONcommand (ifenabled).*

3 OPERATIONcommandenable.0 On/offportionoftheOPERATIONcommanddisabled.

1 OPERATIONcommandenabled.

2 CONTROLnpinenable.0 CONTROLnpindisabled.

1 CONTROLnpinenabled.

1 CONTROLnpinpolarity.0 Activelow(drivelowtoturnonthepowersupplies).

1 Activehigh(drivehightoturnonthepowersupplies).

0 CONTROLnpinturn-offaction.0 Usestheprogrammedturn-offdelay(soft-off).

1 Turnsoffthepowersuppliesimmediately.



Figure 5. ON_OFF_CONFIG Logical Control

SELECTSEQUENCE0

80h/40h/00h or 81h/41h/01h

SELECT

OR

OR

XOR

OPERATIONCOMMAND

DEVICEPOWER-ON

CONTROL0 PIN

AND 00

1

1

AND

AND

AND

BIT 1 BIT 3 BIT 2 BIT 5 BIT 4ON_OFF_CONFIG

SELECTSEQUENCE1

80h/40h/00h or 82h/42h/02h

SELECT

OR

AND

XORCONTROL1 PIN

OR

0

1

0

1

AND

AND

AND

NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS. SHADED BLOCKS ARE PMBus COMMANDS.



CLEAR_FAULTS (03h)The CLEAR_FAULTS command is used to clear anylatched fault or warning bits in the status registers that have been set and also unconditionally deasserts the ALERT output. This command clears all bits simultaneously. It also clears the POR and WATCHDOG_INT bits in theSTATUS_MFR_SPECIFICregister.TheCLEAR_FAULTScommand does not cause a power supply that has latched offforafaultconditiontorestart.ThestateofthePSENnoutputs under fault conditions are not affected by this command and changes only if commanded through the OPERATION command or the CONTROLn pins. If afaultisstillpresentaftertheCLEAR_FAULTScommandisexecuted, the fault status bit is immediately set again, but ALERT is not reasserted. ALERT is only asserted again when a new fault or warning is detected that occurs after the CLEAR_FAULTScommandisexecuted.Thiscommandiswrite-only. There is no data byte for this command.

WRITE_PROTECT (10h)The WRITE_PROTECT command is used to provide protection against accidental changes to the device’s oper-ating memory. All supported commands can have their parameters read, regardless of the WRITE_PROTECTsettings. The WRITE_PROTECT message content isdescribed in Table 14.

Device Configuration Data Management

The device stores configuration data in both nonvolatile flash memory and volatile RAM. The PMBus engine managesthedeviceconfigurationdata.SeeFigure6.The flash memory has three separate arrays for configuration parameters,whereas theRAMonly hasasinglearray.WhenaPMBuscommand iswritten to thedevice,itisalwayswrittentotheRAM.Whenthedeviceis shipped from the factory, the MAIN and BACKUPflash memory arrays are identical and are configured as shown in Table 3. TheSINGLEarrayisempty.ThereisasetoffivePMBuscommandsthatcanbeusedtotransferdatabetweentheflashandRAMarrays.Thesecommands are described in Table 15.

Figure 6. Device Configuration Data Management

Table 14. WRITE_PROTECT (10h) Command Byte

Table 15. Memory Transfer PMBus Commands

Note: No fault or error is generated if the host attempts to write to a protected area.

COMMAND BYTE MEANING80h DisablesallwritesexcepttheWRITE_PROTECTcommand.40h DisablesallwritesexcepttheWRITE_PROTECT,OPERATION,andPAGEcommands.

20h DisablesallwritesexcepttheWRITE_PROTECT,OPERATION,PAGE,andON_OFF_CONFIGcommands.

00h Enableswritesforallcommands(default).

PMBus COMMAND RESULTING MEMORY TRANSFERSTORE_DEFAULT_ALL CopiesRAMOPERATINGtotheflashMAIN.RESTORE_DEFAULT_ALL CopiestheflashMAINtoRAMOPERATING.

MFR_STORE_ALLCODE=00h CopiesRAMOPERATINGtotheflashMAIN.CODE=01h CopiesRAMOPERATINGtotheflashBACKUP.

MFR_RESTORE_ALLCODE=00h CopiestheflashMAINarraytoRAMOPERATING.CODE=01h CopiestheflashBACKUPtoRAMOPERATING.

MFR_STORE_SINGLE CopiesRAMOPERATING(singleparameter)totheflashSINGLE.

MAIN

CONFIGURATION

CONFIGURATION

FLASH

RAM

BACKUPOPERATING

SINGLE

PMBusCONTROL ANDMONITORING

ENGINE



STORE_DEFAULT_ALL (11h)TheSTORE_DEFAULT_ALLcommandinstructsthedeviceto copy RAM OPERATING to the flash MAIN memoryarray.Notallinformationisstored.Onlyconfigurationdatais stored, not any status or operational data. If an error occurs during the transfer, ALERT asserts if enabled and theCMLbitinSTATUS_WORDissetto1.NobitsaresetinSTATUS_CML.Thiscommandiswrite-only.Thereisnodata byte for this command.WhentheSTORE_DEFAULT_ALLcommandis invoked,the device is unresponsive to PMBus commands anddoes not monitor power supplies while transferring the configuration. The time required to complete this task is listed in the Electrical Characteristics section. The MFR_STORE_SINGLE command allows a single command to be stored in much less time.USER NOTE: VDD must be above 2.9V for the device to performtheSTORE_DEFAULT_ALLcommand.

RESTORE_DEFAULT_ALL (12h)The RESTORE_DEFAULT_ALL command instructs thedevice to copy the flash MAIN memory array to RAMOPERATING.TheRESTORE_DEFAULT_ALLcommandshould only be executed when the device is not operating the power supplies. This command is write-only. There is no data byte for this command. When RESTORE_DEFAULT_ALLisissued,thedataischeckedforvaliditybeforebeingtransferred.IftheMAINarrayiscorrupt,thedevicesetsbit1ofSTATUS_CMLandloadstheBACKUPcopy. If the BACKUP copy is corrupt, then the devicesets bit 2 of STATUS_CML and remains in a null statewithall pins (exceptSCLandSDA) inhigh impedance.The FAULTn pin(s) are also asserted. To resolve thedata corruption, the configuration data must be written to RAMOPERATINGandSTORE_DEFAULT_ALLmustbeissued, followed by a device reset.Uponadevicepower-onreset,oranydevicereset, thiscommand is automatically executed by the device without PMBusactionrequired.

MFR_STORE_ALL (EEh)TheMFR_STORE_ALLcommandinstructsthedevicetocopyRAMOPERATINGtoeithertheflashMAINmemoryarray(CODE=00h)ortheflashBACKUPmemoryarray(CODE = 01h). This command is write-only. There is 1data byte for this command, which is the CODE. TheCODE is either 00h to instruct the device to copy intotheMAINarray,or01h tocopy into theBACKUParray.

AllotherCODEvaluesareignored.Notallinformationisstored. Only configuration data is stored, not any status or operational data. If an error occurs during the transfer, ALERTasserts ifenabledand theCMLbit inSTATUS_WORDissetto1.NobitsaresetinSTATUS_CML.NotethatiftheCODEis00h,thenthiscommandoperatesthesameasSTORE_DEFAULT_ALL.

When the MFR_STORE_ALL command is invoked,the device is unresponsive to PMBus commands anddoes not monitor power supplies while transferring the configuration. The time required to complete this task is listed in the Electrical Characteristics section. The MFR_STORE_SINGLE command allows a single command to be stored in much less time.USER NOTE: VDD must be above 2.9V for the device to performtheMFR_STORE_ALLcommand.

MFR_RESTORE_ALL (EFh)TheMFR_RESTORE_ALLcommandinstructsthedeviceto copy either the flash MAIN memory array (CODE =00h)ortheflashBACKUPmemoryarray(CODE=01h)toRAMOPERATING.Thiscommandiswrite-only.Thereis 1 data byte for this command, which is the CODE.The CODE is either 00h to instruct the device to copyfrom theMAINarray or 01h to copy from theBACKUParray.AllotherCODEvaluesareignored.NotethatiftheCODEis00h,thenthiscommandoperatesthesameasRESTORE_DEFAULT_ALL.

The MFR_RESTORE_ALL command should only beexecuted when the device is not operating the power supplies.WhenMFR_RESTORE_ALLisissued,thedataischeckedfor validity before being transferred. If the MAIN arrayis corrupt, the device sets bit 1 ofSTATUS_CML. If theBACKUP array is corrupt, then the device sets bit 2 ofSTATUS_CML.Nootheractionistakenbythedevice.Toresolve the data corruption, the configuration data must be writtentoRAMOPERATINGandSTORE_DEFAULT_ALLorMFR_STORE_ALLmustbeissued.

CODE=00h CopyRAMOPERATINGtoflashMAINCODE=01h CopyRAMOPERATINGtoflashBACKUP

CODE=00h CopyflashMAINtoRAMOPERATINGCODE=01h CopyflashBACKUPtoRAMOPERATING



MFR_STORE_SINGLE (FCh)MFR_STORE_SINGLE is a read/write word commandthat instructs the device to transfer a single configuration parameter fromRAMOPERATING to the flashSINGLEmemoryarray.TheupperbytecontainsthePAGEandthelowerbytecontainsthePMBuscommandthatshouldbestored.Forexample,iftheTON_DELAYparameterforthepower supply controlledbyPAGE4needs tobestoredto flash, 0460h would be written with this command.Whenread,thiscommandreportsthelastsinglePAGE/ command written to flash. This command can be used while the device is operating the power supplies. If an error occurs during the transfer, ALERT asserts if enabled and theCMLbit inSTATUS_WORD isset to1.Nobitsare set in STATUS_CML. The MFR_STORE_SINGLEcommand should only be invoked a maximum of 85times before either a device reset is issued or a device power cycle occurs, or the RESTORE_DEFAULT_ALLcommand is invoked. Once the MFR_STORE_SINGLEcommand is invoked, the STORE_DEFAULT_ALL andMFR_STORE_ALL commands should not be used untileither a device reset is issued or a device power cycle occurs, or the RESTORE_DEFAULT_ALL command isinvoked.Also,MFR_STORE_SINGLEshouldnotbeusedforcommandsthatarenotstoredinflash.SeeTable 3 for a list of commands that are stored in flash.

USER NOTE: VDD must be above 2.9V for the device to performtheMFR_STORE_SINGLEcommand.

MFR_CRC (FEh)MFR_CRC isa read/writeword command that instructsthe device to report the calculated 16-bit CRC valueof either the RAM OPERATING or the flash MAIN orBACKUP memory arrays. A CRC value for the flashSINGLE array is not available. Only one 16-bit CRC isreportedwith each read ofMFR_CRC.TheCRC valueto be reported is determined by the most previous writtenCODEvalue,asshowninTable 16.Forexample,ifMFR_CRCisfirstwrittenwithaCODEof0001h,thenthe next read of MFR_CRC reports the CRC for theflashBACKUParray. If noCODE value iswritten, than MFR_CRCreturnsFFFFhwhenread.SeeTable 16.

CAPABILITY (19h)TheCAPABILITYcommandisusedtodeterminesomekeycapabilities of the device. TheCAPABILITY command isread-only. The message content is described in Table 17.

VOUT_MODE (20h)TheVOUT_MODEcommand isused to report thedataformatofthedevice.ThedeviceusestheDIRECTformatfor all the voltage-related commands. The value returned is40h,indicatingDIRECTdataformat.Thiscommandisread-only. If a host attempts to write this command, the CMLstatusbitisasserted.SeeTable 5 for the m, b, and Rvaluesforthevariouscommands.

VOUT_MARGIN_HIGH (25h)The VOUT_MARGIN_HIGH command loads the devicewith the voltage to which the power-supply output is to be changedwhen theOPERATION command is set tomargin high. If the power supply is already operating at

Table 16. MFR_CRC (FEh) Command Byte

Table 17. CAPABILITY (19h) Command Byte

MFR_CRC CODE VALUE

MEMORY ARRAY CRC VALUE TO BE REPORTED ON NEXT READ

OF MFR_CRC

0000h FlashMAIN0001h FlashBACKUP0002h RAMOPERATING

BIT NAME MEANING

7 Packet-errorchecking 0=PECnotsupported.

6:5 PMBusspeed 01=Maximumsupportedbusspeedis400kHz.

4 ALERT 1=DevicesupportsanALERToutput(ALERTisenabledinMFR_MODE).0=DevicedoesnotsupportALERToutput(ALERTisdisabledinMFR_MODE).

3:0 Reserved Alwaysreturns0000.



margin high, changing VOUT_MARGIN_HIGH has noeffect on the output voltage. The device only adjusts the power supply to the new VOUT_MARGIN_HIGHvoltage after receiving a newmargin-highOPERATION command.The2databytesareinDIRECTformat.Ifthedevice cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply anddoesthefollowing:1) SetstheMARGINbitinSTATUS_WORD.2) Sets the MARGIN_FAULT bit in STATUS_MFR_

SPECIFIC(PAGES0–11).3) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

VOUT_MARGIN_LOW (26h)The VOUT_MARGIN_LOW command loads the devicewith the voltage to which the power-supply output changes to when the OPERATION command is set tomargin low. If the power supply is already operating at margin low, changing VOUT_MARGIN_LOW has noeffect on the output voltage. The device only adjusts the powersupply to thenewVOUT_MARGIN_LOWvoltageafterreceivinganewmargin-lowOPERATIONcommand.The 2 data bytes are in DIRECT format. If the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and doesthefollowing:1) SetstheMARGINbitinSTATUS_WORD2) Sets the MARGIN_FAULT bit in STATUS_MFR_

SPECIFIC(PAGES0–11)3) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

VOUT_SCALE_MONITOR (2Ah)In applications where the measured power-supply volt-ageisnotequaltothevoltageattheADCinput,VOUT_SCALE_MONITORisused.Forexample,iftheADCinputexpects a 1.8V input for a 12V output, VOUT_SCALE_MONITOR=1.8V/12V=0.15.Inapplicationswherethepower-supply output voltage is greater than the device input range of 2.048V, the output voltage of the powersupply is sensed through a resistive voltage-divider. The resistive voltage-divider reduces or scales the output voltage.ThePMBuscommandsspecifytheactualpower-supply output voltages and not the input voltage to the ADC.Toallowthedevicetomapbetweenthehighpower-supply voltages (such as 12V) and the voltage at theADC input, the VOUT_SCALE_MONITOR command isused.The2databytesareinDIRECTformat.Thisvalueis dimensionless. As an example, if the required scaling factoris0.15,thenVOUT_SCALE_MONITORshouldbesetto1333h(4915/32,767=0.15).SeeTable18.

IOUT_CAL_GAIN (38h)TheIOUT_CAL_GAINcommandisusedtoset theratioof the voltage at theADC input to the sensed current.TheunitsoftheIOUT_CAL_GAINfactorare0.1mΩ.The2databytesare inDIRECTformat.Asanexample, ifa10mΩsenseresistorisusedinconjunctionwitha50V/Vcurrent-senseamplifier, the IOUT_CAL_GAINshouldbesetto500mΩor1388h.USER NOTE:The full-scaleADCvoltageon thedeviceis 2.048V.The value of the sense resistor and current-sense amplifier gain must be scaled appropriately. Also, the maximum voltage at the RSn inputs must be lessthan 4V. The maximum output impedance of the current-senseamplifierislimitedbythesettingoftheADC_TIMEbits inMFR_MODE. See theRecommended Operating Conditions section for details.

Table 18. VOUT_SCALE_MONITOR (2Ah) Examples

*The full-scale ADC voltage on the device is 2.048V. A scaling factor where a 1.8V ADC input represents a nominal 100% voltage level is recommended to allow headroom for margining. Resistor-dividers must be used to measure voltage greater than 1.8V. The maximum source impedance of the resistor-divider is limited by the setting of the ADC_TIME bits in MFR_MODE. See the RecommendedOperatingConditions section for details.

NOMINAL VOLTAGE LEVEL MONITORED

NOMINAL ADC INPUT VOLTAGE LEVEL*

RESISTIVE DIVIDER RATIO

VOUT_SCALE_MONITOR VALUE

1.8Vorless 1.8V 1.0 7FFFh2.5V 1.8V 0.72 5C28h3.3V 1.8V 0.545454 45D1h5V 1.8V 0.36 2E14h

12V 1.8V 0.15 1333h



VOUT_OV_FAULT_LIMIT (40h)The VOUT_OV_FAULT_LIMIT command sets thevalue of the output voltage that causes an output overvoltage fault. The monitored voltage must drop by at least 2% below the limit before the fault is allowed to clear. The 2 data bytes are in DIRECT format. In response to the VOUT_OV_FAULT_LIMITbeingexceeded,thedevicedoesthefollowing:1) SetstheVOUT_OVbitandtheVOUTbitinSTATUS_WORD.2) SetstheVOUT_OV_FAULTbitinSTATUS_VOUT.3) RespondsasspecifiedintheMFR_FAULT_RESPONSE.4) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

VOUT_OV_WARN_LIMIT (42h)The VOUT_OV_WARN_LIMIT command sets the valueof the output voltage that causes an output-voltage high warning. The monitored voltage must drop by at least 2% below the limit before the warning is allowed to clear. This value is typically less than the output overvoltage thresh-oldinVOUT_OV_FAULT_LIMIT.The2databytesareinDIRECT format. In response to theVOUT_OV_WARN_LIMITbeingexceeded,thedevicedoesthefollowing:1) SetstheVOUTbitinSTATUS_WORD.2) SetstheVOUT_OV_WARNbitinSTATUS_VOUT.3) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).

VOUT_UV_WARN_LIMIT (43h)TheVOUT_UV_WARN_LIMITcommandsetsthevalueofthe output voltage that causes an output-voltage low warn-ing. The monitored voltage must increase by at least 2% above the limit before the warning is allowed to clear. This value is typically greater than the output undervoltage-fault threshold in VOUT_UV_FAULT_LIMIT. This warning ismasked until the output voltage reaches the programmed POWER_GOOD_ON for the first time and also duringturn-off when the power supply is disabled. If voltage is being monitored, this should be set to a value greater than100mV.The2databytesareinDIRECTformat.InresponsetoviolationoftheVOUT_UV_WARN_LIMIT,thedevicedoesthefollowing:1) SetstheVOUTbitinSTATUS_WORD.2) SetstheVOUT_UV_WARNbitinSTATUS_VOUT.3) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).

VOUT_UV_FAULT_LIMIT (44h)The VOUT_UV_FAULT_LIMIT command sets the valueof the output voltage that causes an output undervoltage fault. The monitored voltage must increase by at least 2% above the limit before the fault is allowed to clear. This fault is masked until the output voltage reaches the pro-grammedPOWER_GOOD_ON for the first timeandalsoduring turn-off when the power supply is disabled. If voltage is being monitored, this should be set to a value greater than 100mV.The 2 data bytes are inDIRECT format. Inresponsetoviolationof theVOUT_UV_FAULT_LIMIT, thedevicedoesthefollowing:1) SetstheVOUTbitinSTATUS_WORD.2) SetstheVOUT_UV_FAULTbitinSTATUS_VOUT.3) RespondsasspecifiedinMFR_FAULT_RESPONSE.4) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).

IOUT_OC_WARN_LIMIT (46h)The IOUT_OC_WARN_LIMIT command sets the valueof the current that causes an overcurrent warning. The monitored current must decrease by at least 5% below the limit before the warning is allowed to clear. This value is typically less than the overcurrent-fault threshold in IOUT_OC_FAULT_LIMIT.The 2 data bytesare in DIRECT format. In response to violation of theIOUT_OC_WARN_LIMIT,thedevicedoesthefollowing:1) SetstheIOUTbitinSTATUS_WORD.2) SetstheIOUT_OC_WARNbitinSTATUS_IOUT.3) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).

IOUT_OC_FAULT_LIMIT (4Ah)The IOUT_OC_FAULT_LIMIT command sets the valueof the current that causes an overcurrent fault. The monitored current must decrease by at least 5% below the limit before the fault is allowed to clear. This fault is masked until the current is below this limit for the first time.The2databytesareinDIRECTformat.Inresponseto violation of the IOUT_OC_FAULT_LIMIT, the devicedoesthefollowing:1) SetstheIOUTbitinSTATUS_WORD.2) SetstheIOUT_OC_FAULTbitinSTATUS_IOUT.3) Responds as specified in the MFR_FAULT_

RESPONSE.4) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).



OT_FAULT_LIMIT (4Fh)The OT_FAULT_LIMIT command sets the temperature,in degrees Celsius, of the selected temperature sensor at which an overtemperature fault is detected. The moni-tored temperaturemust drop by at least 4°C below thelimit before the fault is allowed to clear. The 2 data bytes are in DIRECT format. In response to the OT_FAULT_LIMITbeingexceeded,thedevicedoesthefollowing:1) SetstheTEMPERATUREbitinSTATUS_WORD.2) Sets theOT_FAULTbit inSTATUS_TEMPERATURE

register.3) RespondsasspecifiedintheMFR_FAULT_RESPONSE.4) NotifiesthehostusingALERTassertion(ifenabledin

MFR_MODE).

OT_WARN_LIMIT (51h)The OT_WARN_LIMIT command sets the temperature,in degrees Celsius, of the selected temperature sensor at which an overtemperature warning is detected. The monitored temperaturemustdropbyat least4°Cbelowthe limit before the warning is allowed to clear. The 2 data bytes are in DIRECT format. In response to theOT_WARN_LIMITbeingexceeded, thedevicedoes thefollowing:1) SetstheTEMPERATUREbitinSTATUS_WORD.2) Sets theOT_WARNbit inSTATUS_TEMPERATURE

register.3) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

POWER_GOOD_ON (5Eh)The POWER_GOOD_ON command sets the value ofthe output voltage that the channel must exceed for a power-good state to be declared on this channel. All channels configured as voltage monitoring, with or without sequencing,shouldhavetheirvoltagesabovePOWER_GOOD_ON for power-supply margining to begin. ThePOWER_GOOD_ONthresholdisalsousedtodetermineifTON_MAX_FAULT_LIMIT isexceeded.ThePOWER_GOOD_ON level should always be set higher than thePOWER_GOOD_OFF level. The 2 data bytes are inDIRECTformat.POWER_GOOD_ON should be set higher than VOUT_UV_FAULT_LIMITandVOUT_UV_WARN_LIMITbecausetheirfunctionality does not become active until the measured output voltagerisesabovethePOWER_GOOD_ONthreshold.

POWER_GOOD_OFF (5Fh)The POWER_GOOD_OFF command sets the value ofthe output voltage that causes the power-good state on this channel to deassert after it has been asserted. The POWER_GOOD_OFF level should always be set lowerthanthePOWER_GOOD_ONlevel.The2databytesareinDIRECTformat.WhentheVOUTlevelofapowersupplyfallsfromgreaterthanPOWER_GOOD_ONtolessthanPOWER_GOOD_OFF,thedevicedoesthefollowing:1) SetsthePOWER_GOOD#bitinSTATUS_WORD.2) Sets the POWER_GOOD# bit in STATUS_MFR_

SPECIFICregister(PAGES0–11).Note: If the POWER_GOOD_ON value is configured tobelowerthanthePOWER_GOOD_OFFvalue,thedevicesetsthePOWER_GOOD_OFFtobeequaltothePOWER_GOOD_ONvalue.Conversely,ifthePOWER_GOOD_OFFvalueisconfiguredtobehigherthanthePOWER_GOOD_ONvalue,thedevicesetsthePOWER_GOOD_ONtobeequaltothePOWER_GOOD_OFFvalue.

TON_DELAY (60h)In the PMBus sequencing configuration, TON_DELAYsets the time, in milliseconds, from when a START condition is received until the PSENn output is asserted.If the PSENn/GPOn output has been configured (withthe MFR_PSEN_CONFIG command) as a PG/GPI or alarm, then this command can be used to delay the assertion oftheoutput.The2databytesareinDIRECTformat.

TOFF_DELAY (64h)TOFF_DELAY sets the time, in milliseconds, from whena STOP condition is received (a soft-off OPERATION command,orthroughtheCONTROLnpinswhenenabled)untilthePSENnoutputisdeasserted.Whencommandedto turn off immediately (either through the OPERATION commandortheCONTROLnpins),theTOFF_DELAYvalueisignored.IfthePSENn/GPOnoutputhasbeenconfigured(withtheMFR_PSEN_CONFIGcommand)asaPG/GPIor alarm, then this command can be used to delay the deassertionoftheoutput.The2databytesareinDIRECTformat.Note: For GPOs configured to assert/deassert basedon Power Good (PG) condition of monitored channels: If the voltage of a monitored channel repeatedly crosses over thePGthresholdduringtheGPO'sTON_DELAYorTOFF_DELAY time, rarely theGPOmight get asserted or deas-serted incorrectly at the end of the delay time. To avoid this scenario,configurebothTON_DELAYandTOFF_DELAYto0ms.Alternatively,setbothTON_DELAYandTOFF_DELAYtononzerovalues.



TON_MAX_FAULT_LIMIT (62h)TON_MAX_FAULT_LIMIT sets an upper time limit, inmilliseconds, from when the PSENn output is asserteduntiltheoutputvoltagecrossesthePOWER_GOOD_ONthreshold.The2databytesareinDIRECTformat.Ifthevalueiszero,thenthelimitisdisabled.InresponsetotheTON_MAX_FAULT_LIMIT being exceeded, the devicedoesthefollowing:

1) SetstheVOUTbitinSTATUS_WORD.2) SetstheTON_MAX_FAULTbitinSTATUS_VOUT.3) RespondsasspecifiedintheMFR_FAULT_


MFR_MODE).

Figure 7. Status Register Organization

VOUT_OV_FAULT

STATUS_VOUT(PAGES 0–15)

LATCHEVENT

FAULT_LOG_FULL

STATUS_CML(ALL PAGES)

EVENT

DATA_FAULTLATCHEVENT

COMM_FAULTLATCHEVENT

MAIN_FAULTLATCHEVENT

BACKUP_FAULTLATCHEVENT

VOUT_OV_WARNLATCHEVENT

VOUT_UV_FAULT OR

OR

OR

AND

CLEAR

OR

STATUS_TEMPERATURE(PAGES 16–20)

OT_WARNEVENT

OT_FAULTLATCH

LATCH

EVENT

STATUS_IOUT(PAGES 0–15)

OC_FAULTLATCHEVENT

OC_WARNLATCHEVENTOR

OR

OR

STATUS_MFR_SPECIFIC(PAGE 0–15)

OFFEVENT

POWER_GOOD#EVENT

MARGIN_FAULTLATCHEVENT

STATUS_MFR_SPECIFIC(PAGES 255)

CONTROL#LATCHEVENT

WATCHDOGLATCHEVENT

FAULT_INPUTLATCHEVENT

LATCHEVENT

VOUT_UV_WARNLATCHEVENT

TON_MAX_FAULTLATCHEVENT

STATUS_WORD(ALL PAGES)

LATCH

TEMPERATURE

SYS_OFF

POWER_GOOD#

VOUT_OV

VOUT

CML

IOUT_OC

IOUT

MARGIN

MFR

CLEAR_FAULTS COMMAND

ALERT RESPONSE ADDRESS (ARA)RECEIVED AND ARBITRATION WON

ALERT BIT IN MFR_MODE

LOCKEVENT

POREVENT

ALERTOUTPUT

NOTE 1: IF AN EVENT IS STILL PRESENT WHEN THE CLEAR_FAULTS COMMAND IS ISSUED, THE BIT IS IMMEDIATELY ASSERTED ONCE AGAIN.NOTE 2: WHEN THE ALERT LATCH IS CLEARED, IF ANY EVENTS ARE STILL PRESENT, THEY DO NOT REASSERT THE ALERT OUTPUT.



STATUS_WORD (79h)The STATUS_WORD command returns 2 bytes of information with a summary of the reason for a fault. The STATUS_WORDmessagecontentisdescribedinTable 19.

STATUS_VOUT (7Ah)TheSTATUS_VOUTcommandreturns1byteofinforma-tion with contents, as described in Table20. All the bits in STATUS_VOUT are latched. When cleared, the bitsare set again if the condition persists, or in the case of TON_MAX_FAULT,whentheeventoccursagain.

Table 19. STATUS_WORD (79h)

Note: The setting of the SYS_OFF and POWER_GOOD# bits do not assert the ALERT signal.

Table 20. STATUS_VOUT (7Ah)

BIT NAME MEANING

15 VOUT Anoutputvoltagefaultorwarning,orTON_MAX_FAULT_LIMITorMFR_TON_SEQ_MAX has occurred.

14 IOUT An overcurrent fault or warning has occurred.13 0 Thisbitalwaysreturnsa0.12 MFR AbitinSTATUS_MFR_SPECIFIC(PAGE=255)hasbeenset.

11 POWER_GOOD# Anypower-supplyvoltagehasfallenfromPOWER_GOOD_ONtolessthanPOWER_GOOD_OFF(logicalORofallthePOWER_GOOD#bitsinSTATUS_MFR_SPECIFIC).

10 0 Thisbitalwaysreturnsa0.9 0 Thisbitalwaysreturnsa0.8 MARGIN A margining fault has occurred.7 0 Thisbitalwaysreturnsa0.

6 SYS_OFF Setwhenanyofthepowersuppliesaresequencedoff(logicalORofalltheOFFbitsin STATUS_MFR_SPECIFC).

5 VOUT_OV An overvoltage fault has occurred.4 IOUT_OC An overcurrent fault has occurred.3 0 Thisbitalwaysreturnsa0.2 TEMPERATURE A temperature fault or warning has occurred.1 CML A communication, memory, or logic fault has occurred.0 0 Thisbitalwaysreturnsa0.

BIT NAME MEANING LATCHED

7 VOUT_OV_FAULT VOUTovervoltagefault. Yes

6 VOUT_OV_WARN VOUTovervoltagewarning. Yes

5 VOUT_UV_WARN VOUTundervoltagewarning. Yes

4 VOUT_UV_FAULT VOUTundervoltagefault. Yes

3 0 Thisbitalwaysreturnsa0. —

2 TON_MAX_FAULT TON_MAX_FAULT_LIMITorMFR_TON_SEQ_MAXfault. Yes





STATUS_IOUT (7Bh)The STATUS_IOUT command returns 1 byte of information with contents, as described in Table 21. All the bitsinSTATUS_IOUTarelatched.Whencleared,thebitsare set again if the condition persists.

STATUS_TEMPERATURE (7Dh)TheSTATUS_TEMPERATUREcommandreturns1byteof information with contents, as described in Table 22. All

thebitsinSTATUS_VOUTarelatched.Whencleared,thebits are set again if the condition persists.

STATUS_CML (7Eh)TheSTATUS_CMLcommandreturns1byteofinformationwith contents, as described in Table 23.TheCOMM_FAULT,DATA_FAULT, MAIN_FAULT, and BACKUP_FAULT bitsarelatched.Whencleared,thebitsaresetagainwhentheevent occurs again. The FAULT_LOG_FULL bit reflectsthe current real-time state of the fault log.

Table 21. STATUS_IOUT (7Bh)

Table 22. STATUS_TEMPERATURE (7Dh)

Table 23. STATUS_CML (7Eh)

Notes: When the NV fault log overwrite is enabled (NV_LOG_OVERWRITE = 1 in MFR_MODE), FAULT_LOG_FULL is set when the fault log is full, but clears when the fault log is overwritten since two fault logs are cleared before each overwrite; the setting of the BACKUP_FAULT and MAIN_FAULT bits do not assert the ALERT signal.

BIT NAME MEANING LATCHED7 IOUT_OC_FAULT IOUTovercurrentfault. Yes6 0 Thisbitalwaysreturnsa0. —5 IOUT_OC_WARN IOUTovercurrentwarning. Yes4 0 Thisbitalwaysreturnsa0. —3 0 Thisbitalwaysreturnsa0. —2 0 Thisbitalwaysreturnsa0. —1 0 Thisbitalwaysreturnsa0. —0 0 Thisbitalwaysreturnsa0. —

BIT NAME MEANING LATCHED7 OT_FAULT Overtemperature fault. Yes6 OT_WARN Overtemperature warning. Yes5 0 Thisbitalwaysreturnsa0. —4 0 Thisbitalwaysreturnsa0. —3 0 Thisbitalwaysreturnsa0. —2 0 Thisbitalwaysreturnsa0. —1 0 Thisbitalwaysreturnsa0. —0 0 Thisbitalwaysreturnsa0. —

BIT NAME MEANING LATCHED7 COMM_FAULT An invalid or unsupported command has been received. Yes6 DATA_FAULT An invalid or unsupported data has been received. Yes5 0 Thisbitalwaysreturnsa0. —4 0 Thisbitalwaysreturnsa0. —3 0 Thisbitalwaysreturnsa0. —2 BACKUP_FAULT FlashBACKUPmemoryarrayiscorrupt. Yes1 MAIN_FAULT FlashMAINmemoryarrayiscorrupt. Yes0 FAULT_LOG_FULL MFR_NV_FAULT_LOGisfullandneedstobecleared. No



Note 1: Setting the LOCK bit or the POR bit does not assert the ALERT signal.Note 2: Applies to all FAULTn inputs. The fault status bit is set even if the FAULTn pin is configured in MFR_NV_LOG_CONFIG to ignore FAULTn pins. If FAULT1 and FAULT2 are disabled, they do not affect this bit.Note 3: Either the CONTROL0 or CONTROL1 pin can set this bit. ON_OFF_CONFIG must be configured to use the CONTROLn pins for this status bit to function.Note 4: This bit is latched when set and can be cleared by either issuing the CLEAR_FAULTS command or by reading the STATUS_MFR_SPECIFIC register.

STATUS_MFR_SPECIFIC (80h)TheSTATUS_MFR_SPECIFICmessagecontentvariesbasedontheselectedPAGE,andisdescribedinTable 24 and Table 25.

Table 24. STATUS_MFR_SPECIFIC (80h) (for PAGES 0–11)

Table 25. STATUS_MFR_SPECIFIC (for PAGE 255)

Note: The setting of the OFF and POWER_GOOD# bits do not assert the ALERT signal.

BIT NAME MEANING LATCHED

7 OFF

Forenabledchannels,thisbitreflectstheoutputstateofthesequencerandissetwhenPSENnisnotassertedduetoeitherasequencingdelayorafault,orthepowersupplybeingturnedoff.Thisbitisalwaysclearedwhenthechannelisdisabled.IfPSENnisreconfiguredasaGPO,thisbitdoesnotreflectthestateofthepin.

No

6 0 Thisbitalwaysreturnsa0. —5 0 Thisbitalwaysreturnsa0. —4 0 Thisbitalwaysreturnsa0. —3 MARGIN_FAULT This bit is set if the device cannot properly close-loop margin the power supply. Yes

2 POWER_GOOD#Thisbitissetwhenthepower-supplyvoltagehasfallenfromPOWER_GOOD_ONtolessthanPOWER_GOOD_OFF.Ondevicereset,thisbitissetuntilthepowersupplyisgreaterthanPOWER_GOOD_ON.

No

1 0 Thisbitalwaysreturnsa0. —0 0 Thisbitalwaysreturnsa0. —

BIT NAME MEANING LATCHED7 LOCK Setwhenthedeviceispasswordprotected(Note1). No6 FAULT_INPUT SeteachtimeanyoftheFAULTninputsarepulledlow(Note2). Yes5 POR SeteachtimeadevicePowerOnReset(POR)occurs(Note4). Yes

4 WATCHDOG_INT Setupondeviceresetwhentheinternalwatchdoghascausedthedevicereset(Note4). Yes

3 CONTROL# SeteachtimetheCONTROLninputsaredeasserted(Note3). Yes2 0 Thisbitalwaysreturnsa0. —1 0 Thisbitalwaysreturnsa0. —0 0 Thisbitalwaysreturnsa0. —



READ_VOUT (8Bh)The READ_VOUT command returns the actual measured(notcommanded)outputvoltage.READ_VOUTis measured and updated every 5ms. If the RSn/GPInis configured to be a general-purpose input (GPI), by configuringtheSELECTbitsinMFR_CHANNEL_CONFIGto either 30h or 34h, then READ_VOUT reports 0000hwhentheGPIninputisinactiveand0001hwhentheGPIninputisactive.The2databytesareinDIRECTformat.

READ_IOUT (8Ch)TheREAD_IOUTcommandreturnsthe latestmeasuredcurrent value. READ_IOUT is measured and updatedevery5ms.The2databytesareinDIRECTformat.

READ_TEMPERATURE_1 (8Dh)The READ_TEMPERATURE_1 command returns thetemperature returned from the temperature sensor. READ_TEMPERATURE_1 returns 7FFFh if the sensoris faulty and 0000h if the sensor is disabled. READ_TEMPERATURE_1 is measured and updated once persecond.The2databytesareinDIRECTformat.

PMBUS_REVISION (98h)The PMBUS_REVISION command returns the revisionofthePMBusspecificationtowhichthedeviceis compliant.Thecommandhas1databyte.Bits7:4indicatethe revision of the PMBus specification Part I to which thedevice is compliant. Bits 3:0 indicate the revision ofthe PMBus specification Part II to which the device is compliant. This command is read-only. The PMBUS_REVISIONvalue returned isalways11h,which indicatesthat the device is compliant with Part I, Rev 1.1 and PartII,Rev1.1.

MFR_ID (99h)TheMFR_IDcommandreturnsthetext(ISO/IEC8859-1)character of the manufacturer’s (Maxim) identification.ThedefaultMFR_IDvalueis4Dh(M).Thiscommandisread-only.

MFR_MODEL (9Ah)The MFR_MODEL command returns the text (ISO/IEC8859-1) character of the device model number. ThedefaultMFR_MODELvalueis59h(Y).Thiscommandisread-only.

MFR_REVISION (9Bh)The MFR_REVISION command returns two text (ISO/IEC8859-1) characters that contain the device revisionnumbers forhardware (upperbyte)and firmware (lowerbyte).Thiscommandisread-only.

MFR_LOCATION (9Ch)The MFR_LOCATION command loads the devicewith text (ISO/IEC 8859-1) characters that identify the facility that manufactures the power supply. The maximum numberofcharactersis8.Thisdataiswrittentointernalflash using the STORE_DEFAULT_ALL command. Thefactory-defaulttextstringvalueis10101010.

MFR_DATE (9Dh)The MFR_DATE command loads the device with text(ISO/IEC 8859-1) characters that identify the date ofmanufacture of the power supply. The maximum number of characters is 8. This data is written to internal flashusingtheSTORE_DEFAULT_ALLcommand.Thefactory-defaulttextstringvalueis10101010.

MFR_SERIAL (9Eh)TheMFR_SERIAL command loads the device with text(ISO/IEC 8859-1) characters that uniquely identify thedevice.Themaximumnumberofcharactersis8.Thisdataiswritten to internal flash using theSTORE_DEFAULT_ALL command. The factory default text string value is10101010.Theupper4bytesofMFR_SERIALareusedto unlock a device that has been password protected. The lower4bytesofMFR_SERIALarenotused tounlockadevice and they can be set to any value.

MFR_MODE (D1h)The MFR_MODE command is used to configure thedevice to support manufacturer-specific commands. The MFR_MODE command should not be changedwhile power supplies are operating. The MFR_MODE command is described in Table 26.



Table 26. MFR_MODE (D1h)BIT NAME MEANING15:14 0 Thesebitsalwaysreturna0.

13 ALERT 0=ALERTdisabled(devicedoesnotrespondtoARA).1=ALERTenabled(devicedoesrespondtoARA).

12 0 Thisbitalwaysreturnsa0.11 SOFT_RESET Thisbitmustbeset,thenclearedandsetagainwithin8msforasoftresettooccur.

10 LOCK

Thisbitmustbeset,thenclearedandsetagainwithin8msforthedevicetobecomepassword protected. This bit is cleared when the password is unlocked. The device should only be locked and then unlocked a maximum of 256 times before either a device reset is issued or a device power cycle occurs.

9:8 0 Thesebitsalwaysreturna0.

7:6 ADC_TIME[1:0]

ThesebitsselecttheADCconversiontime:

ADC_TIME[1:0]00011011

ADCCONVERSIONTIME1µs2µs4µs8µs

5:4 ADC_AVERAGE[1:0]

ThesebitsselectthepostADCconversionaveraging:

ADC_AVERAGE[1:0]00011011

ADCAVERAGINGNoAveraging

Average2SamplesAverage4SamplesAverage8Samples

3:0 IOUT_AVG[3:0]

These bits determine the number of samples to average before reporting the value in MFR_IOUT_AVG:

IOUT_AVG[3:0]00000001001000110100010101100111

AVERAGING1Sample2Samples4Samples8Samples16Samples32Samples64Samples128Samples

IOUT_AVG[3:0]10001001101010111100110111101111

AVERAGING256Samples512Samples1024Samples2048Samples4096Samples8192Samples16,384Samples32,768Samples



MFR_PSEN_CONFIG (D2h)The MFR_PSEN_CONFIG command is used to con-figure the individual PSENn/GPOn (where n = 0–11)outputs. This command should not be changed while the powersuppliesareoperating.TheMFR_PSEN_CONFIG command is described in Table 27 and shown in Figure8.EachPSENn/GPOnpincanbeindependentlyconfiguredusingtheSELECT[2:0]bitstooneofthefollowing: Enableanddisabledpowersupplies (SELECT[2:0]=

000) Forcepinassertion(SELECT[2:0]=001) Forcepindeassertion(SELECT[2:0]=010) Assertwhenallenabledchannelpower-good(PG)or

GPIareasserted(SELECT[2:0]=011) Assert when any enabled alarm goes active

(SELECT[2:0]=100)If thePSENn/GPOnoutput is configured to enable anddisable power supplies (SELECT[2:0] = 000), then theassociated input channel must also be configured to monitorvoltageandtosequencebysettingtheSELECTbits in MFR_CHANNEL_CONFIG to 10h. See the MFR_CHANNEL_CONFIG (E4h) for more details.

Also, each PSENn/GPOn pin can be independently configured to be active high or active low and either push-pulloropendrainusingtheHI_LOandPP_ODbits,respectively.If SELECT[2:0] = 011, the PSENn/GPOn output is configured to assert when some combination of power goods (PGs) and general-purpose inputs (GPIs) fromeach channel are asserted. The channels that should be used in this combination are selected using the PG_GPI_SELECT bits 31:16. If the PG_GPI_SELECTbit is cleared, then the associated channel is not used in the logical combination toassert theGPOnoutput. IfthePG_GPI_SELECTbitisset,thenthePGorGPIfromthis channel is used in the logical combination to assert or deassert theGPOn output.This function is useful increating system power-good signals.If SELECT[2:0] = 100, the PSENn/GPOn output is configured to assert when any of the enabled channel alarms goes active. The channel alarms are enabled with theALARM_SELECTbits31:16.IftheALARM_SELECTbit is cleared, then the alarm from this channel is blocked. If the ALARM_SELECT bit is set, the alarm from thischannelisroutedtoanORfunctionsuchthatanyenabledalarm asserts the GPOn output. The alarm function ischosen with the ALARM_CONFIG bits in the MFR_FAULT_RESPONSEcommand.ThisfunctionisusefulisinsystemdebugorforenablingsystemstatusLEDs.

Table 27. MFR_PSEN_CONFIG (D2h)BIT NAME MEANING

31:16 PG_GPI_SELECTALARM_SELECT

ThesebitsareonlyusedifSELECT[2:0]=011or100.Eachbitcorrespondstoonechannel(devicechannelN+16=bitnumber):

SELECT[2:0] BITFUNCTION

011Whenthisbitiscleared,thepowergood(PG)orGPIfromchannelNisnotusedinthelogicalANDtoasserttheGPOnoutput.Whenthisbitisset,thePGorGPIisused.

100Whenthisbitiscleared,thealarmfromchannelNisblockedfromthelogicalORtoasserttheGPOnoutput.Whenthisbitisset,thealarmsignalisroutedtothelogicalOR.


7 PP_OD 0=PSEN/GPOpush-pulloutput1=PSEN/GPOopen-drainoutput

6 HI_LO 0=PSEN/GPOactivelow1=PSEN/GPOactivehigh




Table 27. MFR_PSEN_CONFIG (D2h) (continued)

*For proper sequencing, the SELECT bits in MFR_CHANNEL_CONFIG must set to 10h.

Figure 8. MFR_PSEN_CONFIG Functional Logic

BIT NAME MEANING

2:0 SELECT[2:0]

Thesebitsdeterminethefunctionselectedonthepin:

SELECT[2:0]000001010011100101

11x

PSENn/GPOnPINFUNCTIONSELECTEDPSENoperation.*ForceGPOassertion.ForceGPOdeassertion.PG/GPIoperation(usebits31:16).Alarmoperation(usebits31:16). FAULT2specialfunction(onlyPAGE10); SEQspecialfunction(onlyPAGE11).Reserved.

FORCE GPO ASSERTION

FORCE GPO DEASSERTION

TON_DELAY

TOFF_DELAY

OR

OR

AND16

10

16

16

16

16

SELECT

SELECT

000

001

010

100

011

NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS.SHADED BLOCKS ARE PMBus COMMANDS.

PSENx(x = 0–11)

SELECTALARM0–ALARM15

ANDAND


BITS 31:16 BITS 2:0 BIT 6 BIT 7MFR_PSEN_CONFIG

NOT AVAILABLE FORSEQ OR FAULT2

OR FORCE GPO ASSERTIONOR DEASSERTION

NOT AVAILABLE FORSEQ OR FAULT2

ACTIVE HIGH/LOW

OPEN DRAIN/PUSH-PULLPSENx/GPOx(x = 0–9)

PSEN10GPO10FAULT2

PSEN11GPO11SEQ

FAULT2

SEQ



Delay FunctionIf a delay is configured either on or off, the input must be continuously static through the delay time before the outputchangesstate.SeetheFigure9.

MFR_VOUT_PEAK (D4h)TheMFR_VOUT_PEAKcommandreturnsthemaximumactualmeasuredoutputvoltage.Toresetthisvalueto0,writetothiscommandwithadatavalueof0.Anyvalueswritten to this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECTformat.

MFR_IOUT_PEAK (D5h)TheMFR_IOUT_PEAKcommand returns themaximumactualmeasuredcurrent.Toresetthisvalueto0,writetothiscommandwithadatavalueof0.Anyvalueswrittentothis command are used as a comparison for future peak updates.The2databytesareinDIRECTformat.

MFR_TEMPERATURE_PEAK (D6h)TheMFR_TEMPERATURE_PEAKcommandreturnsthemaximum measured temperature. To reset this value to its lowest value, write to this command with a data value of8000h.Anyothervalueswrittenbythiscommandareused as a comparison for future peak updates. The 2 data bytesareinDIRECTformat.

MFR_VOUT_MIN (D7h)The MFR_VOUT_MIN command returns the minimumactual measured output voltage. To reset this value, write to thiscommandwithadatavalueof7FFFh.Anyvalues written to this command are used as a comparison for futureminimumupdates.The2databytesareinDIRECTformat.

MFR_FW_SERIAL (E0h)The MFR_FW_SERIAL command stores the internalfirmware version loaded onto the device. This is a 16-bit unsigned integer. The command is read-only.

MFR_IOUT_AVG (E2h)The MFR_IOUT_AVG command returns the calculatedaverage current. The number of samples collected in the average before reporting the value inMFR_IOUT_AVGis configuredusing the IOUT_AVGbits inMFR_MODE.Writestothiscommandareignored.The2databytesareinDIRECTformat.

MFR_NV_LOG_CONFIG (D8h)The MFR_NV_LOG_CONFIG command is used to configure the operation of the nonvolatile fault logging in the device. The MFR_NV_LOG_CONFIG command isdescribed in Table28.

Figure 9. Input-to-Output Delay Action

INPUT

OUTPUT

ON DELAY ON DELAYOFF DELAY OFF DELAY



Table 28. MFR_NV_LOG_CONFIG (D8h)

*The device clears two fault logs at a time when overwrite is enabled.

BIT NAME MEANING

15 FORCE_NV_FAULT_LOG

Settingthisbittoa1,forcesthedevicetologdataintothenonvolatilefaultlog.Onceset, the device clears this bit when the action is completed. Host must set again for subsequentaction.Ifanerroroccursduringthisaction,thedevicesetstheCMLbitinSTATUS_WORD;nobitsaresetinSTATUS_CML.

14 CLEAR_NV_FAULT_LOG

Settingthisbittoa1,forcesthedevicetoclearthenonvolatilefaultlogbywritingFFhtoall byte locations. Once set, the device clears this bit when the action is completed. Host must set again for subsequent action. If an error occurs during this action, the device setstheCMLbitinSTATUS_WORD;nobitsaresetinSTATUS_CML.Whileclearingthefaultlog,monitoringisstoppedandcommandsshouldnotbesenttothePMBusport.


10 NV_LOG_T0_CONFIG

ThisbitdeterminesthesourceofthedatawrittenintotheT0locationofeachpagewhena nonvolatile fault log is written.0=LogthelastregularcollectionintervalADCreading1=ReadthelatestADCvaluebeforelogging

9 NV_LOG_OVERWRITE 0=DonotoverwritetheNVfaultlog1=OverwritetheNVfaultlogonceitisfull*

8:7 NV_LOG_DEPTH[1:0]

ThesebitsdeterminethedepthoftheNVfaultlog:

NV_LOG_DEPTH[1:0]00011011

ADCRESULTCOLLECTIONINTERVAL

5ms20ms80ms160ms

NVFAULTLOGDEPTH15ms60ms240ms480ms

N NV_LOG_FAULT0 0=DonotwriteNVfaultlogwhenFAULT0 pin is externally pulled low.1=WriteNVfaultlogwhenFAULT0 pin is externally pulled low.

5 NV_LOG_FAULT10=DonotwriteNVfaultlogwhenFAULT1 pin is externally pulled low.1=WriteNVfaultlogwhenFAULT1 pin is externally pulled low and the FAULT1 pin is enabled.

4 NV_LOG_FAULT20=DonotwriteNVfaultlogwhenFAULT2 pin is externally pulled low.1=WriteNVfaultlogwhenFAULT2 pin is externally pulled low and the FAULT2 pin is enabled.




MFR_FAULT_RESPONSE (D9h)The MFR_FAULT_RESPONSE command speci-fies the response to each fault or warning condition supportedbythedevice.Inresponsetoafault/warning,thedevicealwaysreportsthefault/warningintheappropriate status register and asserts the ALERToutput(ifenabledin MFR_MODE).A CML fault cannot cause any deviceaction other than setting the status bit and asserting the ALERToutput.TheMFR_FAULT_RESPONSEcommandis described in Table30 and shown in Figure10.For each fault type (overvoltage or overcurrent, under-voltage, sequencing error, and overtemperature), eachchannel can be independently configured to respond in the requiredmannerwith theRESPONSEbits inMFR_FAULT_RESPONSE. Ifchannels0–11areconfigured tolatchoffforaparticularfault,thechannelturnsoff(eitherimmediatelyorafter theTOFF_DELAYasconfiguredorcommanded)andalsoassertoneormoreoftheFAULTn pinsiftheyareenabledwithbits18:16inMFR_FAULT_RESPONSE.The channel remains off and theFAULTn outputs remain asserted until either the master power control is toggled using the OPERATION command orCONTROLnpinsasconfiguredintheON_OFF_CONFIGcommandor thedevice is resetorpowercycled.Whenthe device attempts to sequence the power supplies on, all enabled faults must be cleared before the channel is allowed to power-on or the FAULTn pins deasserted. If channels12–15areconfiguredtolatchoff,theyrespondlikechannels0–11;however,allthepowersuppliesmustbe turned off before they are allowed to turn back on.If the channel is configured to retry for a particular fault, the channel turns off (either immediately or after theTOFF_DELAY as configured or commanded) and alsoassert one or more the FAULTn pins if they are enabled withbits18:16 inMFR_FAULT_RESPONSE.Thechan-nel remains off and the FAULTn outputs remain asserted forthetimeconfiguredinMFR_FAULT_RETRY.AfterthetimeinMFR_FAULT_RETRYexpires,thedeviceattemptsto sequence the power supplies back on as long as all the enabled faults in the channel are cleared. If all the enabled faults are cleared, then the device deasserts all the FAULTn pins it asserted and as long as no other channels have asserted the FAULTn pins it has been

configured to monitor with bits 26:24 in MFR_FAULT_RESPONSE,thepower-upsequencingbegins.GlobalchannelsmustassertaFAULTn pin and respond to that FAULTn pin for the channel to shut down.

LOCAL vs. GLOBAL ChannelsWith the MFR_FAULT_RESPONSE command (bit 14),each power-supply channel can be tagged as either being LOCALorGLOBAL.Whenbit14 iscleared, thechannelis configured as a LOCAL channel, whichmeans that adetected fault only affects this channel (or page). Withthe RESPONSE bits in the MFR_FAULT_RESPONSEcommand, the device can be configured to respond differ-entlytoeachpossiblefault.Whenbit14isset,thechannelis configured as a GLOBAL channel which means thata detected fault on this channel can assert all enabled FAULTn outputs. The FAULTn outputs that are enabled are selectedwithbits18:16.OnlyGLOBALchannelsrespondto FAULTn pins that are asserted. The FAULTn pins that the channel should respond to are assigned with bits 26:24.LOCALchannelsdonotrespondtothefaultpins.

GLOBAL Channels Respond to FAULTn AssertionBits 26:24 in the MFR_FAULT_RESPONSE commandare used to configureGLOBAL channels to respond orignore one or more of the FAULTn pins when they are asserted. When one or more of the enabled FAULTn pinsisasserted,thechanneleitherdeassertsthePSENnoutput immediatelyorafter theTOFF_DELAYaccordingto the configuration of bit 0 in the ON_OFF_CONFIGcommand.ThechannelcontinuestodeassertthePSENnoutput until all enabled FAULTnpinsdeassert.Whenallenabled FAULTn pins deassert, the channel sequences on as configured if no channel faults are present.

Temperature Fault ResponseA temperature fault is declared when any of the enabled temperature sensors detect a fault. A temperature fault actsgloballyandcanaffectallofthepowersupplies.Forall global supplies, the worst-case fault response of all global channels is applied. If this response is latchoff or retry, all FAULTn pins that are programmed to be asserted by any of the global channels will be asserted. All local channels respond independently, as programmed in that channel’sMFR_FAULT_RESPONSE.



Fault Detection Before Power-On SequencingBeforeanypower-supplychannel isenabledorFAULTn output deasserted, the device checks for overvoltage, overcurrent, and overtemperature faults (but not forundervoltage) if the channel is configured for a faultresponsetoeitherlatchoff(RESPONSE[1:0]=01)orretry(RESPONSE[1:0]=10)intheMFR_FAULT_REPSONSEcommand. Undervoltage faults are detected when thepower supply turns on and fails to reach the power-good level,andtheTON_MAX_FAULT_LIMITisexceededandthedevicetakesfaultactionasconfigured.SeeTable 29.

Logging Faults into MFR_NV_FAULT_LOGIf bit 15 of MFR_FAULT_RESPONSE is set, faults arelogged into the on-board nonvolatile fault log for this channel unless the response for the associated fault is con-figuredtotakenoaction(RESPONSE[1:0]=00).Tokeepfrom needlessly filling the fault log with excessive data, the following rules are applied when subsequent faults occur. Whenovervoltage faults occurs, subsequent overvoltagefaults on this channel are not written to the fault log until eithertheCLEAR_FAULTScommandisissuedoradevicereset occurs. The same rule applies to overcurrent, under-voltage, overtemperature, and sequencing faults (seeTable30 and Figure10).

Table 29. Fault Monitoring States


FAULT REQUIRED DEVICE CONFIGURATION FOR ACTIVE MONITORING WHEN MONITORED

Overvoltage • VoltageMonitoringEnabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG) Continuous monitoring

Undervoltage • VoltageMonitoringEnabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG)

Stopmonitoringwhilethepowersupplyisoff;startmonitoringwhenvoltageexceedsthePOWER_GOOD_ONlevel

Overcurrent • CurrentMonitoringEnabled (SELECT[5:0]=22hinMFR_CHANNEL_CONFIG) Continuous monitoring

Power-UpTime • SequencingEnabled (SELECT[5:0]=10hinMFR_CHANNEL_CONFIG) Monitored only during power on sequence

Overtemperature • TemperatureSensorEnabled (ENABLE=1inMFR_TEMP_SENSOR_CONFIG) Continuous monitoring



Note 1: ChannelsconfiguredtomonitorcurrentmustbeconfiguredasGLOBAL.AlsoPAGES12–15mustbeconfiguredasGLOBAL.Note 2: TheFILTERselectiondoesnotapplytotemperatureorsequencingfaults.Note 3: AllenabledtemperaturesensorfaultsarelogicallyORedtogether.Note 4: If the channel is configured to measure current, these bits are ignored.Note 5: ThesebitsareignoredforPAGES12–15.Note 6: Dependsonwhetherthechannelisconfiguredtomonitorvoltageorcurrent.

Table 30. MFR_FAULT_RESPONSE (D9h)BIT NAME MEANING31:27 0 Thesebitsalwaysreturna0.

26 FAULT2_RESPONSE_ENABLE 0=FAULT2 response disabled1=FAULT2 response enabled




18 FAULT2_ASSERT_ENABLE 0=FAULT2 assertion disabled1=FAULT2 assertion enabled



15 NV_LOG 0=DonotlogthefaultintoMFR_NV_FAULT_LOG1=LogthefaultintoMFR_NV_FAULT_LOG

14 GLOBAL 0=LOCAL(affectonlytheselectedpage)1=GLOBAL(Note1).

13:12 FILTER[1:0]

Continuous excursion time before a fault or warning is declaredandactionistaken(Note2).00=Immediate01=2ms10=3ms11=4ms

11 0 Thisbitalwaysreturnsa0.10:8 ALARM_CONFIG[2:0] SeeTable31.7:6 OT_FAULT_LIMIT_RESPONSE[1:0] SeeTables32and33(Note3).

5:4 TON_MAX_FAULT_LIMIT_RESPONSE[1:0](alsoappliestoMFR_TON_SEQ_MAX) SeeTables32and33(Notes4and5).

3:2 VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] SeeTables32and33(Note4).

1:0 VOUT_OV_FAULT_LIMIT_RESPONSE[1:0]IOUT_OC_FAULT_LIMIT_RESPONSE[1:0] SeeTables32and33(Note6).



Table 31. ALARM_CONFIG Codes

Figure 10. MFR_FAULT_RESPONSE Operation

ALARM_CONFIG[2:0] ALARM CONDITION ALARM CRITERIA000 None —001 Sequencingfault Faultonly010 Undervoltageonly Faultonly011 Undervoltageonly Faultorwarning100 Overvoltage/overcurrentonly Faultonly101 Overvoltage/overcurrentonly Faultorwarning110 Undervoltageorovervoltage/overcurrent Faultonly111 Undervoltageorovervoltage/overcurrent Faultorwarning


BITS 13:12 BITS 10:8 BITS 7:0 BIT 15 BIT 14 BIT 16 BIT 17 BIT 18

MFR_PWM_CONFIG

MFR_PSEN_CONFIG

16

ALARM0–ALARM15 LOCAL0–LOCAL11

AND ORFAULT0

FAULT2

FAULT1

FAULT0OVERVOLTAGEOVERCURRENT

UNDERVOLTAGE

SEQUENCINGERROR

OVER-TEMPERATURE

MONITORING16 CHANNELS

FILTER

FILTER

01 (LATCH OFF)

LATCHOFFOR

RETRYANDNV

LOG

OR

OV/OC 10 (RETRY)11 (LOG ONLY)

01 (LATCH OFF)

UV

SEQ

OT

AND

OR

10 (RETRY)11 (LOG ONLY)

01 (LATCH OFF)10 (RETRY)11 (LOG ONLY)

01 (LATCH OFF)10 (RETRY)11 (LOG ONLY)

INTERNALDS75LVDS75LVDS75LVDS75LV

ALARM_CONFIG

FAULTRESPONSE

MFR_FAULT_RETRY

MFR_FAULT_RESPONSE

MFR_NV_FAULT_LOG

GLOBAL/LOCAL

SELECT

16AND OR PWM7

GPO19FAULT1SELECT

PWM7/GPO19

16AND OR

SELECTPSEN10/

GPO10

PSEN10GPO10FAULT2



Note 1: ALERT is asserted if enabled when a new status bit is set. A status bit is latched when a particular fault occurs that causes a fault response.

Note 2: Fault-freedoesnotincludeundervoltage.

Note 1: ALERT is asserted if enabled when a new status bit is set. A status bit is latched when a particular fault occurs that causes a fault response.

Note 2: Fault-freedoesnotincludeundervoltage.

Table 32. MFR_FAULT_RESPONSE Codes for GLOBAL Channels

Table 33. MFR_FAULT_RESPONSE Codes for LOCAL ChannelsRESPONSE[1:0] FAULT RESPONSE

11• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.• Continues operation.

10(Retry)

• ShutsdownthepowersupplybydeassertingthePSENnoutput.• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.• WaitsforthetimeconfiguredinMFR_FAULT_RETRYandrestartsthesupplyiffault-free(Note2).

01(Latchoff)

• LatchesoffthepowersupplybydeassertingthePSENnoutput.• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.

00 • Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• Continues operation without any action.

RESPONSE[1:0] FAULT RESPONSE

11• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.• Continues operation.

10(Retry)

• Asserts all enabled FAULTn outputs.• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.• WaitsforthetimeconfiguredinMFR_FAULT_RETRYandthendeasserttheFAULTn outputs that were

assertediffault-free(Note2).

01(Latchoff)

• Asserts all enabled FAULTn outputs.• Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• LogsfaultintoMFR_NV_FAULT_LOGifNV_LOG=1.

00 • Setsthecorrespondingfaultbitintheappropriatestatusregister(Note1).• Continues operation without any action.



Alarm Output FunctionalityAny of the GPOn pins can be configured to outputthe alarm signals. See the MFR_PWM_CONFIG andMFR_PSEN_CONFIG commands for details. When anundervoltage or overvoltage/overcurrent alarm is occurr ing, the output remains asserted as long as the alarm continues. When a sequencing fault occurs, the alarmpin remains asserted until either a CLEAR_FAULTS command is received, or a master power control off input isreceivedwitheithertheOPERATIONcommandortheCONTROLnpins.

MFR_FAULT_RETRY (DAh)TheMFR_FAULT_RETRYcommandsetsthedelaytimebetween channel shutdown due to fault event and its restarting if the fault response is configured to retry. This command value is used for all fault responses.The retry timer starts when the fault occurs. If the faulty channelhasbeenconfiguredtoassertoneormoreFAULTpins, theFAULTpinsareasserted.Foranundervoltagefault happening on a channel configured for sequencing(MFR_CHANNEL_CONFIG[5:0]=10h),theFAULTpin(s)deasserts immediately when the retry timer expires. If the channel is configured for voltage monitoring (MFR_CHANNEL_CONFIG [5:0]= 20h) the FAULT pindeasserts when the retry timer expires if no fault con-dition is present. For all other fault events, the FAULTpin(s) deasserts when retry timer expires if no fault ispresent.MFR_FAULT_RETRYshouldbeconfiguredwithavaluelargerthanthelargestsystemTOFF_DELAY.The2databytesareinDIRECTformat.

MFR_NV_FAULT_LOG (DCh)Datafromeachofthe15nonvolatilefault logsisconsti-tuted (in nonvolatile memory) as a block of 255 bytes.Executing the MFR_NV_FAULT_LOG command usingthe Read 32 SMBus protocol, each block of 255 bytescan be read back from the device in packets of 4 bytes. Alternatively, the MFR_NV_FAULT_LOG can also beexecuted to read back a block of 255 bytes by using the BlockReadSMBus protocol except that the devicedoes not report the Byte Count during read back. TheMFR_NV_FAULT_LOG commandmust be executed 15times to dump the complete nonvolatile fault log. If the returned fault log isallFFs (exceptbytes0and1), thisindicates that this fault log has not been written by the device. As the device is operating, it is reading the latest operating conditions for voltage, current, and temperature and updating the status registers. All this information is stored in on-boardRAM.Whena fault is detected (ifso enabled in MFR_FAULT_RESPONSE), the deviceautomatically logs this information to one of the 15 nonvolatile fault logs. After 15 faults have been written,bit0ofSTATUS_CMLissetandthedevicecanbe configured (with the NV_LOG_OVERWRITE bit inMFR_NV_LOG_CONFIG)toeitherstopwritingadditionalfault logs or write over the oldest data. The host can clear thefaultlogbysettingtheCLEAR_NV_FAULT_LOGbitin MFR_NV_LOG_CONFIG.Ifapowersupplyisnotenabledto measure voltage, current, or if a temperature sensor is disabled, theassociated fault logpositionreturns0000h(seeFigure11).

Figure 11. MFR_NV_FAULT_LOG

RAM

FAULT_LOG_INDEXFAULT_LOG_COUNTMFR_TIME_COUNT

STATUS_WORDSTATUS_VOUT/STATUS_IOUT

STATUS_MFR_SPECIFICSTATUS_CML

STATUS_TEMPERATUREREAD_VOUT/READ_IOUT (3 READINGS)

READ_TEMPERATURE_1MFR_VOUT_PEAK/MFR_IOUT_PEAK

MFR_TEMPERATURE_PEAKMFR_VOUT_MIN

EACH FAULT IS WRITTENINTO THE NEXT FAULT LOG

EACH COMMAND READACCESSES THE NEXT FAULT LOG

FAULTOCCURRENCE

MFR_NV_FAULT_LOG

FAULT LOG INDEX 0(255 BYTES)




FLASH



There is a FAULT_LOG_COUNT (16-bit counter) at thebeginning of each fault log that indicates which fault log is the latest. This counter rolls over should more than 65,535 faults be logged. This counter is not cleared when the CLEAR_NV_FAULT_LOG bit in MFR_NV_LOG_CONFIGistoggled.The255bytesreturnedbytheMFR_NV_FAULT_LOGcommandaredescribedinTable 34.

If an error occurs while the device is attempting to write to orclear theMFR_NV_FAULT_LOG, thedevicesets theCMLbitinSTATUS_WORD(nobitsaresetinSTATUS_CML)andALERTisasserted(ifenabledinMFR_MODE).USER NOTE: VDD must be above 2.9V for the device to clearorlogdataintoMFR_NV_FAULT_LOG.

Table 34. MFR_NV_FAULT_LOG (DCh)BYTE PARAMETER BYTE PARAMETER0 00h/FAULT_LOG_INDEX 128 READ_VOUT/READ_IOUTT1PAGE112 FAULT_LOG_COUNT 130 READ_VOUT/READ_IOUTT2PAGE114 MFR_TIME_COUNT(LSW) 132 READ_VOUT/READ_IOUTT0PAGE126 MFR_TIME_COUNT(MSW) 134 READ_VOUT/READ_IOUTT1PAGE128 0000h 136 READ_VOUT/READ_IOUTT2PAGE1210 STATUS_CML/00h 138 READ_VOUT/READ_IOUTT0PAGE1312 STATUS_WORD 140 READ_VOUT/READ_IOUTT1PAGE1314 STATUS_VOUT/STATUS_IOUTPAGES0/1 142 READ_VOUT/READ_IOUTT2PAGE1316 STATUS_VOUT/STATUS_IOUTPAGES2/3 144 READ_VOUT/READ_IOUTT0PAGE1418 STATUS_VOUT/STATUS_IOUTPAGES4/5 146 READ_VOUT/READ_IOUTT1PAGE1420 STATUS_VOUT/STATUS_IOUTPAGES6/7 148 READ_VOUT/READ_IOUTT2PAGE1422 STATUS_VOUT/STATUS_IOUTPAGES8/9 150 READ_VOUT/READ_IOUTT0PAGE1524 STATUS_VOUT/STATUS_IOUTPAGES10/11 152 READ_VOUT/READ_IOUTT1PAGE1526 STATUS_VOUT/STATUS_IOUTPAGES12/13 154 READ_VOUT/READ_IOUTT2PAGE1528 STATUS_VOUT/STATUS_IOUTPAGES14/15 156 0000h30 STATUS_MFR_SPECIFICPAGES0/1 158 0000h32 STATUS_MFR_SPECIFICPAGES2/3 160 0000h34 STATUS_MFR_SPECIFICPAGES4/5 162 0000h36 STATUS_MFR_SPECIFICPAGES6/7 164 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE038 STATUS_MFR_SPECIFICPAGES8/9 166 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE140 STATUS_MFR_SPECIFICPAGES10/11 168 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE242 STATUS_MFR_SPECIFICPAGES12/13 170 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE344 STATUS_MFR_SPECIFICPAGES14/15 172 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE446 STATUS_MFR_SPECIFICPAGE255/00h 174 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE548 STATUS_TEMPERATUREPAGES16/17 176 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE650 STATUS_TEMPERATUREPAGES18/19 178 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE752 STATUS_TEMPERATUREPAGE20/00h 180 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE854 CURRENT_CHANNELS(Note4) 182 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE956 0000h 184 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE1058 0000h 186 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE11



Note 1: LOG_VALIDissettoDDhifthefaultlogcontainsvaliddata. Note 2: ForREAD_VOUT,READ_IOUT,T2istheoldestreadingandT0isthenewestreading. Note 3: STATUS_VOUT/STATUS_IOUTandREAD_VOUT/STATUS_IOUTdependonwhetherthechannelisconfiguredtomonitor voltage or current. Note 4: CURRENT_CHANNELSisabitmask(0=voltage/1=current)indicatingwhichchannelsareenabledforcurrentmeasurement.

Table 34. MFR_NV_FAULT_LOG (DCh) (continued)BYTE PARAMETER BYTE PARAMETER60 READ_VOUT/READ_IOUTT0PAGE0(Notes2,3) 188 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE1262 READ_VOUT/READ_IOUTT1PAGE0(Notes2,3) 190 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE1364 READ_VOUT/READ_IOUTT2PAGE0(Notes2,3) 192 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE1466 READ_VOUT/READ_IOUTT0PAGE1 194 MFR_VOUT_PEAK/MFR_IOUT_PEAKPAGE1568 READ_VOUT/READ_IOUTT1PAGE1 196 MFR_VOUT_MINPAGE070 READ_VOUT/READ_IOUTT2PAGE1 198 MFR_VOUT_MINPAGE172 READ_VOUT/READ_IOUTT0PAGE2 200 MFR_VOUT_MINPAGE274 READ_VOUT/READ_IOUTT1PAGE2 202 MFR_VOUT_MINPAGE376 READ_VOUT/READ_IOUTT2PAGE2 204 MFR_VOUT_MINPAGE478 READ_VOUT/READ_IOUTT0PAGE3 206 MFR_VOUT_MINPAGE580 READ_VOUT/READ_IOUTT1PAGE3 208 MFR_VOUT_MINPAGE682 READ_VOUT/READ_IOUTT2PAGE3 210 MFR_VOUT_MINPAGE784 READ_VOUT/READ_IOUTT0PAGE4 212 MFR_VOUT_MINPAGE886 READ_VOUT/READ_IOUTT1PAGE4 214 MFR_VOUT_MINPAGE988 READ_VOUT/READ_IOUTT2PAGE4 216 MFR_VOUT_MINPAGE1090 READ_VOUT/READ_IOUTT0PAGE5 218 MFR_VOUT_MINPAGE1192 READ_VOUT/READ_IOUTT1PAGE5 220 MFR_VOUT_MINPAGE1294 READ_VOUT/READ_IOUTT2PAGE5 222 MFR_VOUT_MINPAGE1396 READ_VOUT/READ_IOUTT0PAGE6 224 MFR_VOUT_MINPAGE1498 READ_VOUT/READ_IOUTT1PAGE6 226 MFR_VOUT_MINPAGE15100 READ_VOUT/READ_IOUTT2PAGE6 228 0000h102 READ_VOUT/READ_IOUTT0PAGE7 230 0000h104 READ_VOUT/READ_IOUTT1PAGE7 232 READ_TEMPERATURE_1PAGE16106 READ_VOUT/READ_IOUTT2PAGE7 234 READ_TEMPERATURE_1PAGE17108 READ_VOUT/READ_IOUTT0PAGE8 236 READ_TEMPERATURE_1PAGE18110 READ_VOUT/READ_IOUTT1PAGE8 238 READ_TEMPERATURE_1PAGE19112 READ_VOUT/READ_IOUTT2PAGE8 240 READ_TEMPERATURE_1PAGE20114 READ_VOUT/READ_IOUTT0PAGE9 242 MFR_TEMPERATURE_PEAKPAGE16116 READ_VOUT/READ_IOUTT1PAGE9 244 MFR_TEMPERATURE_PEAKPAGE17118 READ_VOUT/READ_IOUTT2PAGE9 246 MFR_TEMPERATURE_PEAKPAGE18120 READ_VOUT/READ_IOUTT0PAGE10 248 MFR_TEMPERATURE_PEAKPAGE19122 READ_VOUT/READ_IOUTT1PAGE10 250 MFR_TEMPERATURE_PEAKPAGE20124 READ_VOUT/READ_IOUTT2PAGE10 252 0000h126 READ_VOUT/READ_IOUTT0PAGE11 254 LOG_VALID(Note1)



MFR_TIME_COUNT (DDh)The MFR_TIME_COUNT command returns the currentvalue of a real-time counter that increments every 5ms, 20ms, 80ms, or 160ms depending on the configurationoftheNV_LOG_DEPTHbitsinMFR_NV_LOG_CONFIG.This counter is useful in determining the time between multiple faults. The counter is a 32-bit value that rolls over.Thecountisresettozeroupondevicepowercycleor RST action,orasoft-reset.MFR_TIME_COUNTcanbe preset to any value and starts counting up from the preset value.

MFR_CHANNEL_CONFIG (E4h)The MFR_CHANNEL_CONFIG command is used to configure the monitoring channels (PAGES 0–15).This command should not be changed while the power supplies are operating. The MFR_CHANNEL_CONFIGcommand is described in Table 35 and shown in Figure12.Each RSn/GPIn pin can be independently configuredusingtheSELECT[5:0]bitstooneofthefollowing: Monitor voltage; use the monitored voltage for

sequencing(SELECT[5:0]=10h) Monitor voltage; do not use for sequencing

(SELECT[5:0]=20h) Monitorcurrent(SELECT[5:0]=22h) Readvoltageonly;donotmonitorforvoltagefaultsor

warnings(SELECT[5:0]=21h)

Readcurrentonly;donotmonitorforcurrentfaultsorwarnings(SELECT[5:0]=23h)

General-purposeinput(GPI);activelow(SELECT[5:0]=30h)

General-purposeinput(GPI);activehigh(SELECT[5:0]=34h)

Inputisdisabled(SELECT[5:0]=00h)If the monitoring channel is configured to monitor volt-age for sequencing (SELECT[5:0] = 10h), then the associated PSENn output channelmust also be config-uredforcontrollingpowersuppliesbysettingtheSELECTbits in MFR_PSEN_CONFIG to 000. See the MFR_PSEN_CONFIGcommanddescriptionformoredetails.When the RSn/GPIn pins are configured as general- purpose inputs (GPIs) the READ_VOUT commandreports0000hwhenthepin is inactiveand0001hwhenthe pin is active.Also, when the RSn/GPIn pins are configured to monitor voltage (SELECT[5:0] = 10h or 20h) or act asGPI(SELECT[5:0]=30hor34h),eachchannelcanbeindependently configured to generate a signature signal at the SEQ output. This would facilitate event-based sequencing(inmultipledevicesystems),byindicatingthatthis power supply has reached its POWER_GOOD_ONlevel and other channels can now proceed with their power-up.



Table 35. MFR_CHANNEL_CONFIG (E4h)

*For proper sequencing, the SELECT bits in MFR_PSEN_CONFIG must be set to 000.

BIT NAME MEANING


11:8 SEQ_GENERATE

These bits determine which SEQ signature the channel should generate after crossing the POWER_GOOD_ONlevel:

0000 Disabled 1000 Signature8 0001 Signature1 1001 Signature9 0010 Signature2 1010 Signature10 0011 Signature3 1011 Signature11 0100 Signature4 1100 Signature12 0101 Signature5 1101 Signature13 0110 Signature6 1110 Signature14 0111 Signature7 1111 Signature15


5:0 SELECT[5:0]

ThesebitsselectthefunctionoftheRSn/GPInpins:

SELECT[5:0] SELECTEDCHANNELFUNCTION 010000(10h) Sequencing+voltagemonitoring(onlyvalidforPAGES0–11)* 100000(20h) Voltagemonitoring(nosequencing) 100010(22h) Currentmonitoring 100001(21h) Voltagereadonly 100011(23h) Currentreadonly 110000(30h) General-purposeinputactivelow 110100(34h) General-purposeinputactivehigh 000000(00h) Disabled



Figure 12. MFR_CHANNEL_CONFIG Command

PG0–PG15

MFR_FAULT_RESPONSE

MFR_FAULT_RESPONSE

VOUT_SCALE_MONITOR

POWER_GOOD_ONPOWER_GOOD_OFF

LOGIC LEVEL(ACTIVE HIGH/LOW)

SEQ GENERATE

SELECTOR

MFR_PSEN_CONFIG

READ_VOUT

GPI0–GPI15

SEQ

VOUT_OV_FAULT_LIMITVOUT_OV_WARN_LIMITVOUT_UV_FAULT_LIMITVOUT_UV_WARN_LIMIT

IOUT_CAL_GAIN

READ_IOUT

IOUT_OC_FAULT_LIMITIOUT_OC_WARN_LIMIT

VOUT_SCALE_MONITOR READ_VOUT

IOUT_CAL_GAIN READ_IOUT

READ_VOUT

MFR_CHANNEL_CONFIG

NOTE: SIGNALS LISTED IN ITALICS ARE INTERNAL SIGNALS THAT CONNECT TO OTHER DEVICE FUNCTIONS. SHADED BLOCKS ARE PMBUS COMMAND

PSEN11GPO11SEQ

PSEN11/GPO11

16

VOLTAGE MONITORSELECT = 10h or 20h

CURRENT MONITORSELECT = 22h

VOLTAGE READ-ONLYSELECT = 21h

CURRENT READ-ONLYSELECT = 23h

GENERAL-PURPOSE INPUTSELECT = 30h or 34h

DISABLEDSELECT = 00h

RS0–RS15GPI0–GPI15

0000h WHEN INACTIVE0001h WHEN ACTIVE

BITS 11:8BITS 5:0



Table 36. Fault-Monitoring States


FAULT REQUIRED DEVICE CONFIGURATION FOR ACTIVE MONITORING WHEN MONITORED

Overvoltage • Voltage monitoring enabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG) Continuous monitoring.

Undervoltage/ PowerGood

• Voltage monitoring enabled (SELECT[5:0]=10hor20hinMFR_CHANNEL_CONFIG)

• IfSELECT[5:0]=10h(monitorandsequencemode),stopsmonitoringwhenPSENisdisabled.PowerGoodstartsmonitoringwhenPSENisenabledandUndervoltagemonitoringstartswhenvoltageexceedsthePOWER_GOOD_ONlevel.

• IfSELECT[5:0]=20h(monitoronlymode),starts monitoring when the voltage exceeds thePOWER_GOOD_ONlevel.

Overcurrent • Current monitoring enabled (SELECT[5:0]=22hinMFR_CHANNEL_CONFIG) Continuous monitoring.

Power-UpTime • Sequencingenabled (SELECT[5:0]=10hinMFR_CHANNEL_CONFIG) Monitored only during power-on sequence.

Overtemperature • Temperature sensor enabled (ENABLE=1inMFR_TEMP_SENSOR_CONFIG) Continuous monitoring.



MFR_TON_SEQ_MAX (E6h)The MFR_TON_SEQ_MAX command sets an upperlimit, in milliseconds, from a sequencing group (eitherSEQUENCE0orSEQUENCE1,aschosenbytheSEQ_SELECTbit intheMFR_SEQ_CONFIGcommand), initi-ating the power-up sequence until the channel expects to begin its power-up based on an event, which could be eithera logic combinationofpower-good (PG)andGPIsignals or a match on the SEQ pin, as configured with the SELECT bits inMFR_SEQ_CONFIG.The 2 data bytesareinDIRECTformat.Ifthisvalueiszero,thenthelimitisdisabled.InresponsetotheMFR_TON_SEQ_MAXbeingexceeded,thedevicedoesthefollowing:1) SetstheVOUTbitinSTATUS_WORD.2) SetstheTON_MAX_FAULTbitinSTATUS_VOUT.3) Responds as specified in the MFR_FAULT_


MFR_MODE).

MFR_PWM_CONFIG (E7h)TheMFR_PWM_CONFIGcommandisusedtoconfigurethe individualPWMx/GPOy(x=0–7/y=12–19)outputs.This command should not be changed while the power supplies are being PWM margined. The MFR_PWM_CONFIG command is described inTable 37 and shown in Figure13.EachPWMn/GPOnpincanbe independentlyconfiguredusingtheSELECT[2:0]bitstoperformoneofthefollowing: PWMmarginingoperation(SELECT[2:0]=000)

Forcepinassertion(SELECT[2:0]=001) Forcepindeassertion(SELECT[2:0]=010) Assertwhenallenabledchannelpower-good(PG)or

GPIareasserted(SELECT[2:0]=011) Assert when any enabled alarm goes active

(SELECT[2:0]=100)Also,eachPWMn/GPOnpincanbeindependentlyconfig-ured to be active high or active low and either push-pull or opendrainusingtheHI_LOandPP_ODbits,respectively.IfSELECT[2:0]=011, thePWMn/GPOnoutput isconfig-ured to assert when some combination of power-goods (PGs) and GPIs from each channel are asserted. Thechannels that should be used in this combination are selected using the PG_GPI_SELECT bits 31:16. If thePG_GPI_SELECT bit is cleared, then the associated channel is not used in the logical combination to assert the GPOoutput.IfthePG_GPI_SELECTbitisset,thenthePGorGPIfromthatchannelisusedinthelogicalcombinationtoassertordeasserttheGPOnoutput.Thisfunctionisusefulin creating system power-good signals.IfSELECT[2:0]=100,thePWMn/GPOnoutput isconfig-ured to assert when any of the enabled channel alarms go active. The channel alarms are enabled with the ALARM_SELECT bits 31:16. If theALARM_SELECT bitis cleared, then the alarm from that channel is blocked. If theALARM_SELECTbit is set, then thealarm from thatchannelisroutedtoanORfunction,suchthatanyenabledalarm asserts the GPOn output. The alarm function is chosen with the ALARM_CONFIG bits in the MFR_FAULT_RESPONSEcommand.ThisfunctionisusefulforsystemdebugorforenablingsystemstatusLEDs.



Table 37. MFR_PWM_CONFIG (E7h)BIT NAME MEANING

31:16 PG_GPI_SELECTALARM_SELECT

ThesebitsareonlyusedifSELECT[2:0]=011or100;eachbitcorrespondstoonechannel(devicechannelN+16=bitnumber): SELECT[2:0] BITFUNCTION

011 Whenthisbitiscleared,thepowergood(PG)orGPIfromchannelNisnotusedinthelogicalANDtoasserttheGPOnoutput.Whenthisbitisset,thePGorGPIisused.

100 Whenthisbitiscleared,thealarmfromchannelNisblockedfromthelogicalORtoasserttheGPOoutput.Whenthisbitisset,thealarmsignalisroutedtothelogicalOR.

15:12 OFF_DELAY

These bits determine the delay time to pin deassertion; when the pin is operating as a PGn/GPInoralarmpin(SELECT[2:0]=011or100):

OFF_DELAY[3:0] DELAYTIME OFF_DELAY[3:0] DELAYTIME 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 1110 2000ms 0111 100ms 1111 4000ms

11:8 ON_DELAY

These bits determine the delay time to pin assertion; when the pin is operating as a PGn/GPInoralarmpin(SELECT[2:0]=011or100):

ON_DELAY[3:0] DELAYTIME ON_DELAY[3:0] DELAYTIME 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 1110 2000ms 0111 100ms 1111 4000ms

7 PP_OD 0=PWMn/GPOnpush-pulloutput1=PWMn/GPOnopen-drainoutput

6 HI_LO 0=PWMn/GPOnactivelow1=PWMn/GPOnactivehigh


2:0 SELECT[2:0]

Thesebitsdeterminethefunctionselectedonthepin:

SELECT[2:0] PWMn/GPOnPINSELECTEDFUNCTION 000 PWMoperation 001 ForceGPOassertion 010 ForceGPOdeassertion 011 PG/GPIoperation(usebits31:16) 100 Alarmoperation(usebits31:16) 101 FAULT1specialfunction(onlyPAGE7) 11x Reserved



Delay FunctionIf a delay is configured either on or off, the input must be continuously static through the delay time before the outputchangesstate(seeFigure9).

MFR_SEQ_CONFIG (E8h)TheMFR_SEQ_CONFIGcommandisusedtoconfigurethesequencingchannels(PAGES0–11).Thiscommandshould not be changed while the power supplies are operating. The MFR_SEQ_CONFIG command isdescribed in Table38 and shown in Figure2.Eachchannelcanbeindependentlyconfiguredtoinitiatepower-onsequencing,usingtheSELECT[1:0]bits,tooneofthefollowingconditions: Wait for either SEQUENCE0 or SEQUENCE1 from

ON_OFF_CONFIGdecode(SELECT[1:0]=00) Waitforallenabledchannelpower-good(PG)orGPI

tobeasserted(SELECT[1:0]=01) WaitforamatchontheSEQpin(SELECT[2:0]=10)If SELECT[1:0] = 00, then the channel waits for eitherthe SEQUENCE0 or SEQUENCE1 signal to assertbefore powering on. The sequence signal to use is selected with the SEQ_SELECT bit. The SEQUENCE0and SEQUENCE1 signals are generated by decoding

theOPERATIONcommandandCONTROLnpinsusingthe ON_OFF_CONFIG command. See the ON_OFF_CONFIGcommanddescriptionfordetails.Thisselectionwould be used if the channel is being controlled by time-based sequencing.IfSELECT[1:0]=01,thensequencingforthechannelisinitiatedwhensomecombinationof power-goods (PGs)and general-purpose inputs (GPIs) are asserted. Thechannels that should be used in this combination are selected using the PG_GPI_SELECT bits 31:16. If thePG_GPI_SELECT bit is cleared, then the associatedchannel is not used in the logical combination to assert theGPOnoutput.IfthePG_GPI_SELECTbitisset,thenthepowergoodorGPI from thechannel isused in thelogical combination to initiate the power-on sequencing. This selection would be used if the channel is being con-trolled by event-based sequencing.If SELECT[1:0] = 10, then sequencing is initiatedwhenthe channel matches the selected signature on the SEQ pin. The signature to match on is selected with the SEQ_MATCH bits. TheSEQ signal is used to facilitate event-based sequencing in multiple-device systems. This selection would be used if the channel is being controlled by event-based sequencing.

Figure 13. MFR_PWM_CONFIG Functional Logic

FORCE GPO ASSERTION

FORCE GPO DEASSERTION

ON_DELAY

OFF_DELAYOR

OR

AND16 6

16

16

16

16

SELECT

000

001

010

100

011


PWMx(x = 0–7)

SELECTALARM0–ALARM15

ANDAND


BITS 31:16 BITS 2:0 BIT 6BITS 15:8 BIT 7MFR_PWM_CONFIG

NOT AVAILABLE FORPWMn OR FAULT1 OR

FORCE GPO ASSERTIONOR DEASSERTION

NOT AVAILABLE FORPWMn OR FAULT1

ACTIVE HIGH/LOW

OPEN DRAIN/PUSH-PULL

PWMx/GPOy(x = 0–6)(x = 12–18)

PWM7GPO19FAULT1FAULT1



MFR_MARGIN_CONFIG (DFh)The MFR_MARGIN_CONFIG command configuresboth thedigitalPWMnoutputs (PWM0–PWM7)and the externalDS4424currentDAC (ifpresent) tomargin theassociated power supplies. If the PWMn/GPOn pin isconfigured with MFR_PWM_CONFIG for any functionbesides PWM operation, this selection overrides the margining functionality. The MFR_MARGIN_CONFIGcommand is described in Table 39.

Power-Supply Margining OperationFor the power supplies connected to PSEN0–PSEN7(PAGES 0–7), power-supply margining is implementedusing thePWM0–PWM7outputs, respectively.ThePWMfrequency is 312.5kHz. For power supplies connected toPSEN8–PSEN11 (PAGES 8–11), power-supply margin-ing is implemented using the external DS4424DAC out-puts according Table 40. The device close-loop controls the PWM duty cycle or DAC output current setting to

marginthepowersupply.Whenmarginingisnotactive,thePWMnandDACoutputsarehighimpedance.ThedevicemarginsthepowersupplieswhenOPERATIONis set to one of the margin states. Margining of the supplies does not begin until ALL channels that have been config-ured as voltage monitoring (with or without sequencing)have exceeded their programmed POWER_GOOD_ONlevels. When this happens, the PWM or DAC output isenabled and margining is initiated. The device then aver-ages four samples of VOUT for a total time of 20ms. Ifthe measured VOUTand the target (setbyeitherVOUT_MARGIN_HIGHorVOUT_MARGIN_LOW)differ,thePWMdutycycleortheDACsettingisadjustedbyonestep.Thedirection of the duty-cycle adjustment is determined by the SLOPE bit in MFR_MARGIN_CONFIG. Use a positiveslopewhentheDACisdirectlydrivingthereferencevoltageofapowersupply.UseanegativeslopewhentheDACisinjectedintothepowersupply'sfeedbackpinasshowninFigure14.Allchangesto theDACsettingaremadeafteraveraging four samples of VOUTovera20msperiod.

Table 38. MFR_SEQ_CONFIG (E8h)BIT NAME MEANING

31:16 PG_GPI_SELECT

ThesebitsareonlyusedifSELECT[1:0]=01;eachbitcorrespondstoonechannel (devicechannelN+16=bitnumber):Whenthesebitsarecleared,thepowergood(PG)orGPIfromchannelNisnotusedinthelogicalANDtoinitiatepower-onsequencing.Whenthesebitsareset,thePGorGPIisused.


11:8 SEQ_MATCH

These bits determine which SEQ signature the channel must match before initiating poweronsequencing: 0000 Disabled 1000 Signature8 0001 Signature1 1001 Signature9 0010 Signature2 1010 Signature10 0011 Signature3 1011 Signature11 0100 Signature4 1100 Signature12 0101 Signature5 1101 Signature13 0110 Signature6 1110 Signature14 0111 Signature7 1111 Signature15


5:4 SELECT[1:0]

Thesebitsdeterminethesignalthatinitiatespower-onsequencing: SELECTEDPOWER-ON SELECT[1:0] SEQUENCINGCONTROLSIGNAL SEQUENCINGTYPE 00 SEQUENCE0orSEQUENCE1(usebit0) Timebased 01 PG/GPIlogiccombination(usebits31:16) Eventbased 10 SEQMatch(usebits11:8) Eventbased 11 Reserved


0 SEQ_SELECT 0=SEQUENCE01=SEQUENCE1



WhentheOPERATIONcommanddeactivatesmargining,andthemargininghasbeenrunningwith the“IgnoreAllFaults” condition, the device does not beginmonitoringforfaultsfor100msafterthe“MarginOff”inputisreceivedto allow time for the power supplies to return to a normal condition.

Margining FaultsThe device detects two possiblemargining faults. First,if the initialPWMdutycycleorDACstepcausesVOUT to exceed the target value (either high or low, depend-ing on whether the device has been instructed to margin high or low, respectively), this creates a fault. Second,if the target value cannot be reached when the PWMduty cycle or DAC reaches zero or full scale, this also creates a fault. If either margining fault occurs, the device continues attempting to margin the power supply and doesthefollowing:1) SetstheMARGINbitinSTATUS_WORD.2) Sets the MARGIN_FAULT bit in STATUS_MFR_

SPECIFIC(PAGES0–11).3) NotifiesthehostthroughALERTassertion(ifenabled

inMFR_MODE).

If a communication error occurs between the MAX34451 and the external DS4424, a fault occurs when theMAX34451attemptstosettheDACtofullscaleandthetarget margin value is not reached.

DC_DAC ValueThe DC_DAC value for the channels controlled by thePWMn outputs can be determined by the following formula.TheDC_DACvalue for thechannelscontrolledby theexternal currentDAC is automatically configuredbythedeviceandsetto0x00h.

PWMDC_DACvalue=255x(VFB/VDD)where VFB is the power-supply feedback node voltage and VDD is the supply voltage.Example:

VFB=0.8V,VDD=3.3V PWMDC_DACvalue=255x(0.8/3.3)~62d=0x3Eh

PWM/DAC Margining Component SelectionFigure14 shows how to implement margining by inject-ingPWMvoltage intoapower supply’s feedbackpin.Alow-pass filter is connected to thePWMpin to filteroutthe pulsation.Formarginhighoperation,thefollowingequationcalculatesthemaximumallowableresistor:

whereMarginRangeHighisthemaximumrequiredmarginhigh range in percentage.

RV V R

V M inRangeHigh V RR

MHFB

OUT FB

0 3 1

1100

1 1.

arg22

Table 39. MFR_MARGIN_CONFIG (DFh)

Table 40. Power-Supply DAC Outputs

BIT NAME MEANING

15 SLOPE

DACandPWMsettingtoresultingvoltagerelationship:0=Negativeslope DACsourcecurrentresultsinalowervoltage IncreasingPWMdutycycleresultsinalowervoltage1=Positiveslope DACsourcecurrentresultsinahighervoltage DecreasingPWMdutycycleresultsinahighervoltage

14 OPEN_LOOP 0=Normalclosed-loopmargining1=PWMdutycycleorDACvaluesetconstantlytotheDC_DACvaluewhenmargininginvoked


7:0 DC_DAC

This8-bitvaluehastwopurposes:1) WithPWMmargining,itisusedastheinitialPWMdutycyclewhenthedevicebeginstomargina

power supply either up or down.2) Whenbit14isset,thisvalueisusedtosetthePWMdutycycleortheexternalcurrentDAClevel.

PAGE POWER SUPPLY DS4424 OUTPUT8 PSEN8 OUT09 PSEN9 OUT110 PSEN10 OUT211 PSEN11 OUT3



Formarginlowoperation,thefollowingequationcalculatesthemaximumallowableresistor:

whereMarginRangeLowisthemaximumrequiredmarginlow range in percentage and VDD is the supply voltage.To ensure that both the maximum high and low margin rangescanbeachieved,choosea resistor,RPWM, that islowerofRMHandRML.Further,inordertoaccountforthe presence of the ripple filter resistor, choose resistor valuefor‘R’(seeFigure14)whichis4.7kΩlessthanthecalculatedvalueofRPWM.Whenmargininghigh, thedevicesinkscurrent from thefeedback node, and when margining low, the device sourcescurrent into the feedbacknode.Ensure that ‘R’resistorvalueischosensuchthatthePWMsources/sinksnotmorethan200µAmaximumcurrentwhenoperatingatfull margin range.Example:VOUT=1V,VFB=0.6V,VDD=3.3V,R1=33.2kΩ,R2=49.9kΩ,MarginingRange=±10%

Usingtheaboveequations:RMH=98.8kΩ;RML=736.3kΩ.ChooseRPWM=98.8kΩSetRequaltoRPWM-4.7kΩ=94.1kΩDAC“RFS”=(7.75)/(IFBxMarginingrangex120%)where IFB is the feedback node current.Example:

IFB=500µA,marginingrange=±15%DAC“RFS”value=(7.75)/(500µAx15%x120%)=

86kΩNote:40kΩ<RFS<160kΩ

Temperature Sensor OperationThe device can monitor up to five different temperature sen-sors, four external sensors, plus its own internal tempera-ture sensor. The external temperature sensors are all con-nected in parallel to the master I2Cport(MSDAandMSCLpins).ThedevicecansupportuptofourDS75LVdevices.Eachoftheenabledtemperaturesensorsaremeasuredonce per second. The internal temperature sensor is averaged four times to reduce theeffectofnoise.Eachtime the device attempts to read a temperature sensor, it checks for faults.For the internal temperaturesensor,afaultisdefinedasreadinggreaterthan+130°Corlessthan -60°C. For the I2C temperature sensors, a fault is

RV V R

V M inRangeLow VML

FB DD

OUT FB

0 5 1

1100

1

.arg

RR12

Figure 14. Margining Hardware Configurations

FS

RFS

IFB

VFBR

VOUT

PWMn

POWER SUPPLY

RIPPLE FILTER

MAX34451

FB/TRIM4.7kΩ

10nF

IFB

VOUT

OUT

POWER SUPPLY

DS4424

FB/TRIM

R2

R2

R1

R1



defined as a communication access failure. Temperature-sensor faults are reported by setting the temperature reading to 7FFFh.A temperature-sensor fault results in thesettingoftheTEMPERATUREbitinSTATUS_WORDand ALERT isasserted (ifenabled inMFR_MODE).NobitsaresetinSTATUS_TEMPERATURE.Onresetofthedevice,ifthedevicecannotinitializetheexternalDS75LVdevice,theTEMPERATUREbitinSTATUS_WORDissetand ALERT isasserted(ifenabled inMFR_MODE),butthe device does not attempt to reinitialize the DS75LVuntil8000hiswrittentoMFR_TEMP_SENSOR_CONFIG.Reading disabled temperature sensors returns a fixedvalueof0000h.Up to four DS75LV digital temperature sensors can becontrolled by the MAX34451. The A0–A2 pins on theDS75LVshouldbeconfiguredasshowninTable 41. The thermostatfunctionontheDS75LVisnotusedandhencetheO.S.outputshouldbeleftopencircuit.MFR_TEMP_SENSOR_CONFIG (F0h)TheMFR_TEMP_SENSOR_CONFIGcommand is usedtoconfigurethetemperaturesensors.TheMFR_TEMP_SENSOR_CONFIGcommandisdescribedinTable 42.

Applications InformationVDD, VDDA, and REG18 DecouplingTo achieve the best results when using the device, decouple VDD and VDDA power inputs each with a 0.1µFcapacitor. Ifpossible,useahigh-quality,ceramic,

surface-mount capacitor. Surface-mount componentsminimize lead inductance,which improvesperformance,and ceramic capacitors tend to have adequate high- frequencyresponsefordecouplingapplications.Decouplethe REG18 regulator output using 1µF and 10nF capacitorswithamaximumESRof500mΩ.

Open-Drain PinsMSDA, MSCL, SCL, SDA, FAULTn, SEQ, and ALERT are open-drain pins and require external pullup resistors connected to VDDtorealizehighlogiclevels.PSEN0–PSEN11canbeuser-configuredaseitherCMOSpush-pull or open-drain outputs. When configured asopen drain (seeMFR_PSEN_CONFIG), external pullupresistors connected to VDDare required to realize highlogic levels.

Keep-Alive CircuitIn systems where the power to the device may not always bepresent, a keep-alivecircuit consistingofaSchottkydiode and a bulk capacitor can be added to allow the device time to orderly shut down the power supplies it is controlling and write fault log (if configured) to flashmemory before power is lost.

Configuration PortSome applications require the ability to configure thedevicewhenthedevicehasbeenmountedonaPCB.Insuch applications, a 3- or 4-wire header can be added to allow access to the slave I2C pins.

Resistor-Dividers and Source Impedance for RSn InputsThe maximum full-scale voltage on the ADC inputs is2.048V (nominal). A resistor-divider must be used tomeasure voltages greater than 1.8V. The maximumsourceimpedancetotheRSninputsisdeterminedbytheADC_TIMEbitsinMFR_MODE.SeetheRecommended Operating Conditions section for more details.

Protecting Input PinsInapplicationswherevoltagescanbeappliedtotheRSnorCONTROLnsignals,whenVDD or VDDA is grounded, a series 100Ω resistor is recommended to protect thedevice by limiting power dissipation.

Exposed Pad GroundingThedeviceusestheexposedpadof theTQFNpackageas the commonground (VSS) for the entire device.Theexposed pad must be connected to the local ground plane.

Table 41. DS75LV Address Pin Configuration

Table 42. MFR_TEMP_SENSOR_CONFIG (F0h)

PAGE MAX34451 TEMP SENSOR

DS75LV ADDRESS PIN CONFIGURATION

A2 A1 A016 MAX34451 internal — — —17 DS75LV(address90h) 0 0 018 DS75LV(address92h) 0 0 119 DS75LV(address94h) 0 1 020 DS75LV(address96h) 0 1 1

BIT NAME MEANING

15 ENABLE 0=Temperaturesensordisabled1=Temperaturesensorenabled




http://pdfserv.maximintegrated.com/land_patterns/90-0043.PDF

+Denotes a lead(Pb)-free/RoHS-compliant package.T = Tape and reel.*EP = Exposed pad.**MAX34451ETNA4+ and MAX34451ETNA4+T are recommended for all future designs. Note: Part operates over the -40°C to +85°C temperature range.

PART NUMBER PIN-PACKAGE FIRMWARE STATUSMAX34451ETNA2+ 56TQFN-EP* 0005 ACTIVEMAX34451ETNA2+T 56TQFN-EP* 0005 ACTIVEMAX34451ETNA3+ 56TQFN-EP* 0007 ACTIVEMAX34451ETNA3+T 56TQFN-EP* 0007 ACTIVEMAX34451ETNA4+** 56TQFN-EP* 0009 ACTIVEMAX34451ETNA4+T** 56TQFN-EP* 0009 ACTIVE

MAX34451

MSDA

MSCL

PSEN0–PSEN11

VDDA

VDD

DS4424I2C 4-CHANNELCURRENT DAC

(I2C ADDRESS A0h)

OPTIONALMARGINING

SUPPORT FORCHANNELS

8–11

DS75LVI2C TEMPSENSOR

(I2C ADDRESSES90/92/94/96h)

OPTIONALKEEPALIVE

OPTIONAL

OPTIONALCONFIGURATION

ACCESS

OPTIONALREMOTE

TEMPSENSORS(UP TO 4)

SDA

SCL

ALERT

ADDR

3.3V

RST

FAULT0

CONTROL0

CONTROL1

REG18

VSS (EP)

HOSTINTERFACE

POWERCONTROL

PWM0–PWM7

RSG0RSG1

ONLY REQUIREDIF THE MONITOREDVOLTAGE IS > 1.8V

POWERSUPPLY CURRENT-

SENSEAMPLIFIER

OPTIONALCURRENT

MONITORINGLOADIN OUT

TRIMEN

RS0–RS15

Typical Operating Circuit

Ordering Information



REVISIONNUMBER

REVISIONDATE DESCRIPTION PAGES

CHANGED

0 3/13 Initial release —

1 8/13 Added VDD rise time and VDD source impedance to Recommended Operating Conditions table, updated the 7-bit slave addresses in Table 4 2, 17

2 5/15 UpdatedBenefits and Features section and moved Ordering Information to page 1 1, 66

3 4/16

(Firmwareupdate)UpdatedOrdering Information, Table 3, Table 5, Table 7, SEQ Pin Operation section, Clear Faults (03h) section, POWER_GOOD_ONsection,Figure7,Table 25, MFR_VOUT_MIN (D7h) section, MFR_FAULT_RETRY (DAh) section, Table 36, Power-Supply Margining Operation section, DC-DAC Valuesection,PWM/DACMargining Component Selectionsection,Figure14,Keep-Alive Circuit section

1, 15-16, 21-22, 26,32,37-38,41, 46, 53, 57, 63-65

4 3/17 AddedfuturepartstoMAX34451ETNA2+andMAX34451ETNA2+TintheOrdering Information section. 75

5 7/17

UpdatedTable3andTOFF_DELAY (64h), MFR_PSEN_CONFIG (D2h), MFR_NV_FAULT_LOG (DCh), and MFR_PWM_CONFIG (E7h)sections.RemovedfuturepartdesignationsforMAX34451ETNA2+andMAX34451ETNA2+T,andremovedMAX34451ETNA1+andMAX34451ENTA1+T

22, 45, 52, 61,68,75

6 5/18 AddedMAX34451ETNA3+andMAX34451ETNA3+TtotheOrdering Information table. 75

7 6/18

UpdatedTable3,Table4,SMBus/PMBus Operation Examples, and PMBus Operation, POWER_GOOD_ON (5Eh), POWER_GOOD_OFF (5Fh), MFR_NV_FAULT_LOG (DCh) and Power-Supply Margining Operationsections;UpdatedtheOrdering Information table.

22, 24, 27 45, 61, 71, 75

8 9/19 UpdatedOrdering Information 75

9 10/19 UpdatedOrdering Information 75

Revision History

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.


© 2019MaximIntegratedProducts,Inc. 76

For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.

Click here MAX34451 PMBs 16-Channel VI Monitor an 12-Channel … · 2019. 10. 28. · MAX34451 Mus...

Documents

Transcript of Click here MAX34451 PMBs 16-Channel VI Monitor an 12-Channel … · 2019. 10. 28. · MAX34451 Mus...