Design of Automotive Chargersg gFor WPC 1504Charlie Wu
S e p t . 1 7 . 2 0 1 5
Distinguished Member of Technical Staff
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AgendaAgendaWireless Charging in AutomotiveAutomotive Wireless Charging ChallengesAutomotive Wireless Charging ChallengesAutomotive Wireless Transmitter Solution
DesignWireless Charging Software DesignQ&A
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Wireless Charging in Car
Toyota
Honda
Chrysler AudiAudi’s Phone Box
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Wireless Charging Challenges in Automotive
Foreign Object Detection• Foreign Object Detection :Selective and qualitative detection of foreign objects around the system (metallic or magnetic objects) is of key importance due to their ability to absorb energy from the wireless power supply field in the form of heat (parasitic heating) and possibly become a hazard.
CE4A (Consumer Electronics for Automotive)•CE4A (Consumer Electronics for Automotive)― No-Go for all automotive OEM’s:
Radio AM/FM band (AM band)Remote t key (Most systems operate inside existing Qi frequency range)Capacitive switchImmobilizerImmobilizerNFC
― Automotive key points:EnvironmentalHarsh operating temperature rangesHumidity and spill protectionVibration profilesThermal shock
•Shielding effectiveness:The shielding added under the primary and above the secondary is important for the safe operation of wireless power transfer. Without shielding, the magnetic field may interfere with the device or other objects; it may cause battery heating and may circulate current in metallic parts.
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Wireless charging Transmitter – A13 transmitter Litz Wire Coils
Key Features:
Compliant with Wireless Power Consortium (WPC) low power specifications to support up to 5W power transferI t t d di it l d d l tiIntegrated digital demodulationSupport free positioning multiple coils low power transmitter solutions using fixed frequency PWM controlSupport both Resonance Shift and Power Loss FOD methods
Support key FOB and AM band avoidance
Low standby power consumption
Automotive applications design
Support PMA SR1 specifications
AEC-Q100 grade 2 certification
Voltage/current/temperature protectionVoltage/current/temperature protection
Software based solution with Freescale embedded wireless charger software libraries to provide maximum design freedom and product differentiation FreeMASTER GUI tool to enable customization and calibration
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Got WPC Qi certification with WCT1001AVLH: 15010210HKG
Example of PCB type Coil (4 coils) –A33 Transmitter Type
4th coil
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How Freescale Solution Fits for Automotive (1/3)
• SafetySafety− Foreign object detection:
Support resonance shift method for FOD before power transferSupport power loss method for FOD during power transfer
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Support power loss method for FOD during power transferAdditional coils temperature protection
How Freescale Solution Fits for Automotive (2/3)
• Harsh Environment− Alignment Aids
S t i d t il d PCB t ilSupport wire-round type coils and PCB type coilsSupport multi-coil array for fee positioning alignment with large charging area Large z-gap up to 10mm
AEC Q100 certified product− AEC-Q100 certified product− Comprehensive system fault protection: voltage/current/temperature
protectionEmissions/Interferences• Emissions/Interferences− Fixed operating frequency to reduce the emission for wide frequency band − KeyFOB/Radio Interference
S t ti f d ift t d th i t f di t ifiSupport operating frequency drift to reduce the interference according to specific frequency band
− NFC co-existancePartner with Melexis to provide NFC solution for co-existance with WPC
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Partner with Melexis to provide NFC solution for co existance with WPC
How Freescale Solution Fits for Automotive (3/3)
• Low standby power consumption− Support touch sensor for ultra low standby power consumption
S G f− Support analog PING with intermittent controller deep sleep for low standby power consumption
• Vehicle InterfaceS f− Support wide support voltage rage from 9V to 16V
− Ignition interface designed− CAN communication interface
Support to add wireless charging into car network for better managementSupport software updating from HMI
• ProductibilityS ft b d l ti t il id t ti t t f t d i− Software based solution to easily provide automatic test feature during mass production and service
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Analog demodulation in wireless charging
Hardware demodulation circuit
Wireless Charging chipset
Coil current signal
TX Coil
chipset
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Digital demodulation in wireless charging- Low cost and Flexible
Sampling circuit
Coil current signal
WCT1xxxA
ADCDDM software
TX Coil
ADC software module
Benefit Tradeoff
BOM t d d S hi ti t d d d l ti l ithBOM cost reduced Sophisticated demodulation algorithms
PCB area reduced for more compatible applications DSP processing required
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Freescale Wireless Transmitter Software Structure
The basic kernel functions of wireless charging is packed as library form
The add-on/customized functions are provided as API interfaces suchas API interfaces such as FOD, Touch sensor, CAN, NFC, IIC, indicator/buzzer etc.
User is required to write his/her code for those user application code
Sample code projects will be provided for customer reference to speed the development time
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development time
Wireless Transmitter State Machine
SelectionRX removed
PiR t
Retry time expires No start bit and timeout
PingRetry
No packet and timeout
Iden and ConfigSet retry time
according to error type
timeout
Error packet timeoutError protection
Power transfer
Close loop control
Error protection
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Software Development GUI Tool
Freescale wireless charging GUI tool is based on FreeMASTER, and provides: Configuration: System parameters, coil parameters and FOD parametersCalibration: Analog signal sensing coefficients, FOD algorithm coefficientsg g g gDebugging: System real-time status and variables
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WCT1000 / WCT1101* – Single Coil Transmitter IC
WCT1000WCT1000
CoreADC
InverterControl
Isense
Icoil Coil_PWM1
Drive_EN
CoilDis
Coil_PWM2
100MHz
Demod
Vsense
CommFOD
Hardware
100MHz core Support any 5W single coil type Demod
TouchSense
SDA
SCLT_IRQ
Support any 5W single coil typeRun-time calibration capableLow-power (< 30mA PID loop current)32QFN
S ft DebugSoftware
Closed loop PID algorithmForeign Object DetectionDigital demodulation
Optional
TDI
TMS
TCK
TDO
Reset
UA
RT_R
xU
AR
T_Tx
I2C for Touch Sense Interface (low power)
* WCT1101 - Premium
Program memory available to build & customize applicationAdditi l IO t d l tf biliti ( lti h l h
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Additional IOs to expand platform capabilities (e.g. multi-channel charger, NFC, etc.)64LQFP
WCT100xA – Automotive TransmitterHardware
Automotive-specific transmit controller solutionsAutomotive specific transmit controller solutionsSupports full H-bridge, multi-coil topologyStandard option provides additional programmability and communications interfacesPremium option expands on flash and SRAM for expanded programmability Multi-protocol capableWCT1001A & WCT1003A pin-pin compatible in the 64LQFP package
WCT100xADrive EN
Flash
WCT1001A & WCT1003A pin-pin compatible in the 64LQFP package
Coil1_PWM2
CoreADC Inverter
Control
Isense
Tsense
Vsense
Coil1_PWM1
Drive_EN
CoilDis
100MHz
Demod
Vsense
Comm
FOD
Coil1_En
Coil3_EnCoil2_En
SoftwareVoltage control algorithm
D b
TouchSense
LEDSPI 2SCI
DAC
CAN
g gForeign Object DetectionDigital demodulation
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Debug
Optional
LEDSPIx2SCICAN
Q & AQ & A
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