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AureliaAureliaMicroelettronica S.p.A.Microelettronica S.p.A.

Via Giuntini, 13 - I 56023 Cascina (Italy)Phone: +39.050.754260 Fax: +39.050.754261

E-mail: contactus@aurelia-micro.it URL: http://www.aurelia-micro.it

SIRAD 2004

‘CAN BUS PHYSICAL LAYER RAD TEST’

Thanks for their work to:Andrea Candelori

Marco Ceschia

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PROJECT HISTORYPROJECT HISTORY

This design arises from the need to provide space community with a CAN 2.0B protocol with embedded micro-processor and a CAN physical layer up to 1Mbit/s, since space community is adopting CAN communication systems for spaceaircraft and satellite applications.

CAN ISO 11898 standard, that takes in Bosch 2.0 protocol, has a large use in automotive environment, and it is integrated in many commercial technologies, but no rad hard devices are available on the market

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TECHNOLOGY CHOICETECHNOLOGY CHOICE

ISO11898 imposes high voltage technology has to be used for CAN Transceiver implementation.Since no rad hard high voltage technology is available in Europe at low costs, AMS CXZ 0.8um high voltage technology has been selected, product has been rad hardened by design, and rad test has been performed after silicon out to characterize the transceiver behaviour in a radiation environment.Selected technology has been tested in a rad-hard environment to verify Single Event Effects performancesStarting points for the design are:– Philips TJA1054 and PCA82C250 transceiver datasheet– ISO 11898 CAN Standard

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ISO11898 Standard ISO11898 Standard MainMainRequirementsRequirements on CAN on CAN Physical LayerPhysical Layer

To provide a differential representationof a logical bit on two bus wires according to a logic input pin TX , forEMI safe operationTo assure transmission speed up to1Mbps in the high speed versionTo provide common mode immunity in reception modeTo measure the differential representation (recessive ? dominant ?)And return its logic value on a dedicated logic output pin RXTo provide fault protection circuitry and diagnostics on the bus wires

Physical layer goalsPhysical layer goals::

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CAN CAN TransceiverTransceiver Block Block DiagramDiagram

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Layout PhotoLayout Photo

Die SizeDie Size: :

2.5 X 2.4 mm22.5 X 2.4 mm2

TechnologyTechnology: :

0.8um CXZ AMS0.8um CXZ AMS

NumberNumber of of masksmasks: 17: 17

Assembled Assembled in in ceramic ceramic DIL28, DIL28, butbut SO8 SO8 compatiblecompatible

OnlyOnly 8 8 pins have to be pins have to be bondedbonded, , allall the the othersothersare are forfor test test purposes purposes only only

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Chip PhotoChip Photo

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Layout Layout main concernsmain concerns: : SEL and TID SEL and TID tolerancetolerance

Heavy SEL concern because of:the HV process => high sub resistance (20 Ω ∗cm)Underground and overbattery specifications, that require direct polarization for HV n well cathodes

TID should heavily effect on static parameters, because of the relatively large tox (17nm)

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WaveformsWaveforms (2/3)(2/3)

Slew Slew rate control moderate control mode

Uncontrolled Uncontrolled mode, mode, maximum speedmaximum speed

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WaveformsWaveforms (3/3)(3/3)

ReceiverReceiver common mode common mode immunityimmunity testtest

Receiver thresholds Receiver thresholds test D/R and R/Dtest D/R and R/D

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IrradiationIrradiation Test Set UpTest Set Up

CASTA CAN Transceiver

Under

radiation

CASTA CAN Controller

CASTA CAN & Micro Controller

CAN Transceiver

External board

External board

RadiationRadiationboardboard

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Test setup session: mobile diodes on place holder are used for beam monitoring

On the board back side, commercial circuitry protects each device from latch up: current sense for shut off is fully programmable in the range 100mA/2A for each device

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Heavy ions used during 24th/25th November 2003 session

LETLETMevMev xcm2/mgxcm2/mg

Flow Flow ((ionion/cm2 /s)/cm2 /s)IonIon

303016001600Nickel 58Nickel 58

212112001200--1300013000Titane Titane 4848

6666100100--650650Iodine Iodine 127127

4242120120--30003000BromineBromine 7979

12.512.540004000--2500025000ChlorineChlorine 3535

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SEL Cross section versus LET on Tran device Weibull distribution

SEL cross section versus LET TRAN1

1,0E-06

1,0E-05

1,0E-0412,5 21 30 42 66

LET (Mev cm2 / mg)

cros

s se

ctio

n (c

m2)

sigma

fit

Weibullinterpolated threshold forTRAN1 was19 MeV cm2 / mg

Saturationcross section equals2.7E-5 cm2

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SEL Cross section versus LET on Tran device Weibull distribution

SEL cross section versus LET TRAN2

1,0E-06

1,0E-05

1,0E-04

12,5 21 30 42 66

LET (Mev cm2 / mg)

cros

s se

ctio

n (c

m2)

sigmafit

Weibullinterpolated threshold forTRAN2 was18 MeV cm2 / mg

Saturationcross section equals 3.14E-5 cm2

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SEL Cross section versus LET on Tran device Weibull distribution

Averaged cross section versus LET

21

30

4266

1,E-06

1,E-05

1,E-04

10 20 30 40 50 60 70

LET(Mev*cm2/mg)

Cro

ss s

ectio

n(cm

2)

averaged data from TRAN1, TRAN2 averaged data from all transceivers

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Total dose table on Tran devices

ion TR1 dose (rad)

TR2 dose (rad)

TR3 dose (rad)

Chlorine 35E=178MeVLET=12.5 Mev*cm2/mg

6560 600 0

Bromine 79E=250 MevLET=42 Mev*cm2/mg

3203 2815 322

Iodine 127E=289 MeVLET=66 Mev*cm2/mg

528 572 530

Titane 48E=200 MeVLET= 21 Mev*cm2/mg

672 672 3360

Nickel 58E=210 MeVLET=30 Mev*cm2/mg

4800 4800 4800

Total dose 15763 9459 9012

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Transceiver retesting after irradiation

0,000

0,500

1,000

1,500

2,000

2,500

3,000

3,500

(V)

comparing parameters before and after irradiationon TR1 (sample #20): total dose=15763 rad

CAN_L post irr 1,542

CAN_L pre irr 1,540

CAN_H post irr 3,301

CAN_H pre irr 3,350

V15 post irr 1,448

V15 pre irr 1,420

V25 post irr 2,411

V25 pre irr 2,375

V35 post irr 3,318

V35 pre irr 3,262

1

Percentage Gap (p_post-p_pre) /p_pre

CAN_L +0.13%

CAN_H -1.46%

V15 +1.97%

V25 +1.52%

V35 +1.72%

Electrical parameters did not shift as an irradiation effect

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Test structure retesting after irradiation

Ids/Vds characteristics (size 50µm/4µm)

0,00

50,00

100,00

150,00

200,00

250,00

300,00

350,00

400,00

450,00

500,00

0,00 1,00 2,00 3,00 4,00 5,00 6,00

Vds (V)

Ids

(uA

)

VGS=1.45preirrVGS=0.95preirrVGS=1.08preirrVGS=1.64preirrVGS=1.45postirrVGS=0.95postirrVGS=1.08postirrVGS=1.640postirrVGS=1.82preirrVGS=1.82postirr

NN--mos electrical mos electrical characteristics did not characteristics did not move asmove as a total dose a total dose

effecteffect: : percentage errors percentage errors with respect towith respect to the the prepre--

irradiation measurement irradiation measurement resulted resulted inside the inside the

measurement accuracymeasurement accuracy..

Gate Gate Drain Leakage Drain Leakage current still resultedcurrent still resulted

< 10nA< 10nA

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Summary Summary and and conclusionsconclusions

An ISO11898 compliant CAN transceiver has been developed in commercial AMS 0.8um High Voltage technology and it has been tested in a radiation environment at SIRAD irradiation facility. Number of tested sample is 3.

Extrapolated LET threshold from Weibull distribution resulted in 20MeV * cm2 /mg

TID was measured in 15Krad. Leakage tests and static characteristics re-tracing after irradiation showed no degradation in performancesFinally, we thank A. Candelori (Padua INFN) and

M. Ceschia (Padua DEI) for their work during test plan fixing, test setup and irradiation test

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ThankThanks s forforyour attentionyour attention!!