Automotive 77-GHz Radar Module Reference Design With ...

1 SPIFLASHCAN PHYWide VINDC/DCLM53625 RFAntenna ArrayIOIO + AnalogAnalog + RFDigitalDual Buck +BoostLP877xCAN-FD5 VCAN-FD24 AWAR1642 Radar RFFront End +AFE + DSP + CANC opyright 2017, Texas Instruments Incorporated1 TIDUDQ6 December2017 SubmitDocumentationFeedbackCopyright 2017,TexasInstrumentsIncorporatedAutomot ive77-GHzRadarModuleReferenceDesignWithO bjectDataOutputTI Designs:TIDA-01570 Automotive77-GHzRadarModuleReferenceDesi gnWithObjectDataOutputDescriptionThe automotivecamerareferencedesignoffersaco mpletesolutionfor a 76-GHzto onboardpowersuppliesconvertthe automotivebatteryinputto the requiredrails for theradaranalogfrontend (AFE),processors,andcontrollerareanetwor kingwith flexibledatarate (CAN-FD) ,the objectdatatransmitsoverthe includedCAN-FDphysicallayer(PHY).

2 ResourcesTIDA-01570 DesignFolderAWR1642 ProductFolderLP87702-Q1 ProductFolderTPS7A52-Q1 ProductFolderLM53625-Q1 ProductFolderTCAN1042GV-Q1 ProductFolderASKOur E2E ExpertsFeatures Space-OptimizedDesignFits on SinglePCB(Approximately50 mm 71 mm) PowerSupplyOptimizedfor SmallSizeand HighEfficiency Single-Chip76- to 81-GHzAutomotiveRadarSensorIntegratesDSP and MCUand ProvidesObjectDataOverCAN-FD WideVIN36-VOFFB atterySupplyToleratesup to 42 V Diagnosticand MonitoringFunctionsfor ASILBA pplicationsApplications ADASR adarSystems BlindSpotDetection(BSD) LaneChangeAssist(LCA) Front/RearCross-TrafficAlert(F/RCTA) AutonomousEmergencyBraking(AEB) AdaptiveCruiseControl(ACC)An IMPORTANTNOTICEat the end of this TI referencedesignaddressesauthorizeduse, intellectualpropertymattersand otherimportantdisclaimersand December2017 SubmitDocumentationFeedbackCopyright 2017,TexasInstrumentsIncorporatedAutomot ive77-GHzRadarModuleReferenceDesignWithO bjectDataOutput1 SystemDescriptionRadarsensorsare a requirementfor bumpersand side mirrorscan be very smallsensorsimplifiesthe processof meetingthesemarketdemandsand providesa less expensiveapproachto referencedesignaddressestheseconcernsby combininga single-chip.

3 76- to 81-GHzautomotiveradarsensorwith aCAN-FDPHYand providingthe of this functionalityis containedon a 50 71-mm only two connectionsthat the systemrequiresare the batterypowerin and CAN-FDoutThe batterypowerconnectsto the 12-Vinputterminal,J1. The wideVINbuck,LM536253-Q1,is utilizedtoconvertthis 12-Vinputto a LP87702-Q1thentakesthe , ,and ensurea low-noisesupply,the TPS7A52-Q1low-dropoutlinearregulator(LDO )createsa clean1-V rail for the radiofrequency(RF)sectionof the radarsectionof this designutilizesa printed-circuit-board(PCB)etchedantennaw ith two transmitelementsand four usingthis antenna,a modulatedchirpis transmittedandreflectionsare sampledinto the onboarddigitalsignalprocessor(DSP).Witht his information,the sensorcan recorddistance,angle,and velocitymeasurementsfromobjectswithinthe antennafield of designoffersa featureto writeout the objectdatato a centralelectroniccontrolunit (ECU)on theCAN-FDbus at a rate of 5 SystemSpecificationsTable1.

4 Key SystemSpecificationsPARAMETERCOMMENTSMIN TYPMAXUNITVINS upplyvoltageBatteryinput41242 VPTOTALT otalpowerconsumptionVIN= 12 V WCAN-FDDatarate 5 SPIFLASHCAN PHYWide VINDC/DCLM53625 RFAntenna ArrayIOIO + AnalogAnalog + RFDigitalDual Buck +BoostLP877xCAN-FD5 VCAN-FD24 AWAR1642 Radar RFFront End +AFE + DSP + CANC opyright 2017, Texas Instruments December2017 SubmitDocumentationFeedbackCopyright 2017, referencedesignusesthe followingTI products: AWR1642-Q1:This integrated,single-chipfrequency-modulate dcontinuouswave(FMCW)radarsensoris capableof operationin the 76- to deviceis built with TI s low-power45-nmRFCMOS processand enablesunprecedentedlevelsof integrationin an extremely-smallformfactor(SFF).

5 The AWR1642is an idealsolutionfor low-power,self-monitored,ultra-accurater adarsystemsin the automotivespace. LP87702-Q1:This Automotive -qualifiedpowerdeviceis optimizedfor radarapplicationswith a dualhigh-currentbuckconverterand 5-V high switchingfrequencyof up to 4 MHzallowstheuse of smallinductorsand improvessystemperformancebecausethe secondharmonicis out of the IFbandof the LP87702-Q1includesdiagnosticsfunctionssu chas monitoringofthe internaland two externalrails,two programmablepower-goodoutputs,and a windowwatchdog. TPS7A52-Q1:The TPS7A52-Q1is an Automotive -qualified,low-noise2-A linearregulatorwith ultra-low linearregulatorfiltersany powersupplynoisethat emanatesfromthe upstreamswitchingsupplieswhileminimizing dissipationthroughultra-lowdropoutoperat ion.

6 LM536253-Q1:The LM536253-Q1synchronousbuckregulatoris optimizedfor automotiveapplicationsand providesan outputvoltageof 5 V, V, or an LM53625-Q1/LM53635-Q1to regulatefroman inputof 18 V to an outputof V at a fixedfrequencyof deviceto regulatea only All aspectsof the LM53625-Q1/LM53635-Q1are optimizedfor automotiveand inputvoltagerangeup to 36 V, with transienttoleranceup to 42 V, easesinputsurgeprotectiondesign. TCAN1042GV-Q1:This automotiveCANtransceivermeetsthe ISO11898-2(2016)high followingsubsectionsprovidemoreinformati onon eachdeviceand why they havebeenchosenforthis December2017 SubmitDocumentationFeedbackCopyright 2017, a single-chipradarsensorbuilt with four receiversand two RFCMOS technology,the deviceintegratesthe RF and analogsubsystemwith the digitalsubsystemto deliverlowpowerin an SFF for ultra-short-rangeradar(USRR)and short-rangeradar(SRR) deviceis basedon closed-loopphase-locked-loop(PLL)archite cturefor preciseand built-inradioprocessor(BIST)for RF calibrationand ,the sensordevicesupportsan intermediatefrequency(IF)

7 Bandwidthof5 MHzwith an ARM Cortex -R4 FprocessorandTexasInstrumentsC674xDSP(fi xedand floatingpoint),alongwith on-chipRAM, LP87702x-Q1containstwo high-current(up to A) buckconvertersand a 5-V boostfor devicesupportsremotevoltagesensingto compensateIR dropbetweenthe regulatoroutputand the point-of-load(POL),whichimprovesthe accuracyof the deviceis eithercontrolledby an I2C-compatibleserialinterface,enablesign al,or 4-MHzhigh-switchingfrequencyof the LP87702D-Q1allowsthe use of smallinductorsand improvessystemperformanceby pushingthe secondharmonicout of the maximumIF bandof the furtherprotectthe systemfromelectromagneticinterference(EM I),the buckand boostconvertersare programmedto forcedpulse-widthmodulation(PWM)modefor a externalclockis provided,the deviceautomaticallysynchronizesbuckand boostclocksto the integrateddiagnosticfunctionsof the LP87702D-Q1help to reducethe the internalregulatoroutputvoltages, ,and two externalrails can be monitoredthroughtwo devicealso includesa windowwatchdogwithprogrammableopenand closetimesand combinationof low-noise( VRMS), high power-supplyrejectionratio(PSRR),and high outputcurrentcapabilitymakesthe TPS7A52-Q1idealto powernoise-sensitivecomponents,suchas the RFportionof an RF supplyrails ( V) can be overriddenand suppliedwith an.

8 However,this supplymustbe free of excessivenoise,whichcan be detrimentalto TPS7A52-Q1has high PSRR overan extendedbandwidthto ensurethat any upstreamswitchingnoiseat or above1 MHzis TPS7A52-Q1also has very low levelsof intrinsicnoise(as low as VRMS) throughthe use of a ,thesequalitiesmakethis devicea goodchoiceto ensurea ,this deviceis capableof low dropoutoperationwith the use of a higherbias rail. Use of thisrail limitsthe minimalpowerdissipatedacrossthe LDOthat typicallyheatsup the boardand the V to V, usingthe TPS7A52-Q1 enablesa cuts the dissipationby 33%. LM536253-Q1is designedto supporta smallersolutionsize and run at coolertemperaturesin aapplication,whichis a combinationof packagetechnologyand higheroverallefficiencyin minimizeswitchnoiseand minimizedparasiticimpedance,this deviceofferslownoiseemissionwhichhelpsto lowersystemelectromagneticcompatibility( EMC)and assistwith the easeof DC/DCconverteris optimizedfor out-of-standardregulationconditions,whic hcan eitherbefault conditionsor normaloperation(like cold crankand load dump).

9 The LM536253-Q1offersthe fullcapabilityto December2017 SubmitDocumentationFeedbackCopyright 2017, automotiveCANtransceivermeetsthe ISO11898-2(2016) PHYhas a low powerstandbymodewith remotewakerequestand manyprotectionfeaturestoenhancedeviceand PHYwas chosenfor its simplicityand FormFactorThis referencedesignis not intendedto fit any only goal of the designwithregardsto the PCBis to makea compactsolutionthat servesas a mountingholes,the boardmeasuresroughly50 mm 71 mm (2 in in). Figure2 andFigure3 showthe top viewand bottomviewof the PCBTop ViewFigure3. December2017 SubmitDocumentationFeedbackCopyright 2017, the previousFigure1 shows,the radarsensorreferencedesignis intendedto connectdirectlyto voltagesrequiredfor the designare: 5 V for CAN-FDPHY V for radarI/O V for radaranalog,RF, VCO,and CMOS V for radardigitaland SRAM 1 V or V for radaranalogand RFAn automotivebatterysuppliesthe powerinputto this sensor;therefore,the designrequiresa wideVINbuckthat can tolerateup to 40 V as the first stageof the a multi-railpowersupply,whichhas beenspecificallydesignedfor this application,to createthe 5-V, ,and the optionto providethe radaranalogand RF supplyas a the to directlysupplythe radaranalogand RF supplyas a low noise1-Vrail.

10 The latteroptionreducesthe powerdissipatedby the optionmay also reducethe total systempower,dependingon the this Design ,supplythe radaranalogand RF supplyexternallywith a raisingthe to , enoughheadroombecomesavailableto coverthe dropouton the LDOthat producesthe 1-V actionalsoreducesthe powerdissipatedin the LDOby as the inputto the LDO,ratherthanthe nexthighervoltagerail, AWR1642deviceutilizesfour powerrails for its operation:a , supply, analogsupply,and 1-V RF lists the peakcurrentson eachof the averagecurrentconsumptiondependson the chirpprofileand frameconfigurationused;for 1Tx , 4 Rxuse casewith a 50%duty cycleand W of PowerRail V850 mA1 VDependson the interfacesusedon AWR1642In a casewherethe 1-V supplyis derivedfromthe V usinga regulator(suchas in this referencedesign),the V ( ) of 1-V rail blockdiagramof the of the key concernswhenusingthe switchingregulatorsfor the powersupplyis to preventtheswitchingfrequencyof the regulatorfromcouplingontothe analogcircuitrythroughthe supplyor a 4-MHzswitchingfrequency,the AWR1642can the keepthe spurin the RX spectrumof less than 120 dBm(at the LNAinput).