设计参考源码手册1746个zhcs

应1.5V到19V转换电压范 4.5V至14V电源电压范 DDR内存和终止电 普通DC/DC转换

ZHCS475–SEPTEMBER0.8V0.7×VIN

TPS53211是一款装有集成高电流驱动器的单相1.5V19V TPS53211特有跳跃模式解决方案，可在轻负载情 250kHz至1MHz的可编程开关频 UVLO保护。它支持高达19V的转换电压，并且 出电压可调范围0.8V至0.7×VINRDS(on)3mmx3mm,16-QFN

TPS532113mm3mm16-引脚QFN(温度范围为–40°C至85°C。EnableEnable89 5ENPGOODBOOT10PHASE11LGATE12CSN VCCDR1CSPOSCVCCGND Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofCopyright©2011,TexasInstrumentsInstrumentssemiconductorproductsand erstheretoappearsattheCopyright©2011,TexasInstrumentsPRODUCTIONDATAinformationiscurrentasofpublicationdate.ProductsconformtospecificationsperthetermsoftheInstrumentsstandardwarranty.Productionprocessingdoes EnglishDataSheet:necessarilyincludetestingofallThesedeviceshavelimitedbuilt-inESDprotection.TheleadsshouldbeshortedtogetherorthedevicecedinconductivefoamduringstorageorhandlingtopreventelectrostaticdamagetotheMOSgates.ORDERINGOUTPUTECO–40°CtoTapeandnoPb/Br)Mini UMoveroperating-airtemperaturerange(unlessotherwiseInputvoltageVCC,VVVBOOTtoVtransient<VVtransient<VFB,VSEN,VCSP,VVCC>6.8VVVCC≤6.8VVVtransient<200VVVGroundVHumanBodyModelVChargedDeviceModelStoragejunctionOperatingjunctionStressesbeyondthoselistedunderabsolute umratingsmaycausepermanentdamagetothedevice.Thesearestressratingsonlyandfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunder mendedoperatingconditionsisnotimplied.Exposuretoabsolute- um-ratedconditionsforextendedperiodsmayaffectdevicereliability.AllvoltagevaluesarewithrespecttothenetworkgroundterminalunlessotherwiseVoltagevaluesarewithrespecttotheSWTHERMALTHERMAL16Junction-to-case(top)Junction-to-case(bottom)6有关传统和新的热度量的信息，请参阅IC封装热度量应用报告SPRA953MENDEDOPERATINGInputvoltageV BOOTto7transient<7transient<FB,VSEN,CSP,VVCC>6.85VVCC≤6.8OutputvoltageVUGATEtoPHASE,7transient<2007GroundJunctiontemperaturerange,-airtemperature,ELECTRICALoveroperating-airtemperaturerange,VCC=12V,PGND=GND(unlessotherwiseTESTINPUTVCCsupplyNominalinputvoltageVVCCPORRampup;ENVVCCPORVCCDRPORStandbyENpinislow.VVCC=12Rds(on)ofthebootstrapΩDRIVERVCCDRSupplyNominalinputvoltageVVCCDRPORRampup;ENVVCCDRPORVCCDRPORStandbyENpinislow.VVCC=12InternalprecisionreferenceVVREFCloselooptrim.0°C≤TJ≤ERRORUnitygainOpenloopFBInputleakageSourcedfromFBOutputsinkingandsourcingSlew5ENlogicVENlogicENpinSOFTDelayafterENEN=‘HI’to“switchingPGOODstartupdelayPGdelayaftersoft-startRamp4.5V<VVCC<122V)MinimumONDMA umdutyXfSW=1SWITCHINGTypicalswitchingROSC=61.9MinumumswitchingROSC=250umswitchingROSC=141SwitchingfrequencyROSC>12.4TA=SeePSpindescriptionforEnsuredbydesign.NotproductionELECTRICALCHARACTERISTICS(1) overoperating-airtemperaturerange,VCC=12V,PGND=GND(unlessotherwiseTESTGATEIHigh-sidedriversourcing(VBOOT–dto5V,high1ΩHigh-sidedriversinking(VBOOT–dto5V,lowΩLow-sidedriversourcing(VCCDR–GND)=5V,highΩLow-sidedriversinkingVCCDR–GND=5V,lowΩPOWERPGlowerMeasuredatVSENw/r/tPGupperMeasuredatVSENw//rtPGMeasuredatVSENw/r/tPGdelaytimeatTimefromVSENoutof+12.5%ofVREFtoPGlowPGdelaytimeatTimefromVSENoutof–12.5%ofVREFtoPGlowMinimumVCCvoltageforvalidPGatMeasuredatVVCCwith1mA(or2mA)sinkcurrentonPGpinatstartup.1VPGpull-downPulldownvoltagewith4mAsinkVPGleakageHi-Zleakagecurrent,apply6.5VinoffOUTPUTOVERVOLTAGEANDUNDERVOLTAGEOVPMeasuredattheVSENwrt.UVPMeasuredattheVSENwrt.OVPdelayTimefromVSENoutof+12.5%ofVREFtoOVPfaulttUVPDLYUVPdelayTimefromVSENoutof–12.5%ofVREFtoUVPfaultTHERMALThermalLatchoffcontroller,attemptsoft-THSDHYSThermalshutdownControllerstartsagainaftertemperaturehasEnsuredbydesign.NotproductionDEVICE16PINS PIN4ISupplyinputforhigh-sidedrive(bootstrappin).ConnectcapacitorfromthispintoSW8OErroramplifiercompensationterminal.TypeIIIcompensationmethodismendedforICurrentsensenegativeICurrentsensepositive7I9IVoltagefeedback.UseforOVP,UVPandPGDGFeedbackgroundforoutputvoltageGLogicgroundandlow-sidegatedrive3OOutputinductorconnectiontointegratedpower2OLow-sidegatedriveOFrequencyprogramming6OPowergoodoutputflag.Opendrainoutput.Pulluptoanexternalrailviaa5OHigh-sidegatedriveISupplyinputforogcontrol1BiasvoltageforintegratedIOutputvoltageFUNCTIONALBLOCK

+0.8V+0.8Vx+0.8+0.8Vx+0.8+LLOneShotVOUTOCPVCCDR

UDGTYPICAL SwitchingFrequencySwitchingFrequencySupplySupplyCurrent32 0−40−25−10 203550658095110

−40−25−10 203550658095110JunctionTemperature JunctionTemperatureFigure1.VCCCurrentvs.Junction Figure2.SwitchingFrequencyvs.JunctionMeasuredMeasuredatVSENw/r/tPGOODUpper9PowergoodPowergoodHysteresis76543210−40−25−10 203550658095110

UpperPowergoodThreshold−40−25−10 203550658095110JunctionTemperature JunctionTemperature Figure3.PowerGoodHysteresisvs.Junction Figure4.PowerGoodThresholdvs.Junction DETAILEDTheTPS53211isasingle-channelsynchronousbuckcontrollerwithintegratedhigh-currentdrivers.TheTPS53211isusedfor1.5Vupto19Vconversionvoltage,andprovidesoutputvoltagefrom0.8Vto0.7VIN.Itoperateswithprogrbleswitchingfrequencyrangingfrom250kHzto1MHz.Thisdeviceemploysaskipmodesolutionthatoptimizestheefficiencyatlight-loadconditionwithoutcompromisingtheoutputvoltageripple.Thedeviceprovidespre-biasstartup,integratedbootstrapswitch,powergoodfunction,EN/InputUVLOprotection.TheTPS53211isavailableinthe3mmby3mm16-pinQFNpackageandisspecifiedfrom–40°Cto85°C.SwitchingFrequencyTheclockfrequencyisprogrammedbythevalueoftheresistorconnectedfromtheOSCpintoground.Theswitchingfrequencyisprogrblefrom250kHzto1MHz.TherelationbetweenthefrequencyandtheOSCisgivenbyEquation1.fSW200R

78.5ROSCistheresistorconnectedfromtheOSCpintogroundinfSWisthedesiredswitchingfrequencyin Soft-StartThesoft-startfunctionreducestheinrushcurrentduringthestart-up.Aslowrisingreferencevoltageisgeneratedbythesoft-startcircuitryandsenttotheinputoftheerroramplifier.Whenthesoft-startrampvoltageislessthan800mV,theerroramplifierusesthisrampvoltageasthereference.Whentherampvoltagereaches800mV,afixed800mVreferencevoltageisutilizedfortheerroramplifier.Thesoft-startfunctionisimplementedonlywhenVCCandVCCDRareabovetherespectiveUVLOthresholdsandtheENpinisreleased.Whenthesoft-startbegins,thedeviceinitiallywaitsfor1024clockcyclesandthenstartstorampupthereference.Afterthereferencevoltagebeginstorise,thePGOODsignalgoeshighaftera1560clock-cycledelay.UVLOTheTPS53211providesUVLOprotectionfortheinputsupply(VCC)anddriversupply(VCCDR).IfthesupplyvoltageislowerthanUVLOthresholdvoltageminusthehysteresis,thedeviceshutsoff.Whenthevoltagerisesabovethethresholdvoltage,thedevicerestarts.ThetypicalUVLOrisingthresholdis4.25VforVCCand3.32VforVCCDR.Hysteresisof200mVforVCCand220mVforVCCDRarealsoprovidedtopreventglitch.OvercurrentTheTPS53211continuouslymonitorsthecurrentflowingthroughtheinductor.TheinductorDCRcurrentsenseisimplementedbycomparingandmonitoringthedifferencebetweentheCSPandCSNpins.DCRcurrentsensingrequirestimeconstantmatchingbetweentheinductorandthesensingnetwork:L

R

TPS53211hastwolevelOCthresholds:20mVand30mVforthevoltagebetweentheCSPandCSNIfthevoltagebetweentheCSPandCSNpinsexceedsthe20mVcurrentlimitthreshold,anOCcounterstartstoincrementtocounttheoccurrenceoftheovercurrentevents.TheconvertershutsdownimmediaywhentheOCcounterreachesfour(4).TheOCcounterresetsifthedetectedcurrentislowerthantheOCthresholdafteranOCevent.NormaloperationcanonlyberestoredbycyclingtheVCCvoltage.IfthevoltagebetweentheCSPandCSNpinsishigherthan30mV,thedevicelatchesoffimmediay.NormaloperationcanberestoredonlybycyclingtheVCCvoltage.TheTPS53211hasthermalcompensationtoadjusttheOCPthresholdinordertoreducetheinfluenceofinductorDCRvariationduetotemperaturechange.TheOCPlevelhasachangerateof0.35%/°C.OvervoltageandUndervoltageTheTPS53211monitorstheVSENpinvoltagetodetecttheovervoltageandundervoltageconditions.AresistordividerwiththesameratioasontheFBinputis mendedfortheVSENinput.Theovervoltageandundervoltagethresholdsaresetto±13%ofVOUT.WhentheVSENvoltageisgreaterthan113%ofthereference,theovervoltageprotectionisactivated.Thehigh-sideMOSFETturnsoffandthelow-sideMOSFETturnson.NormaloperationcanberestoredonlybycyclingtheVCCpinvoltage.WhentheVSENvoltageislowerthan87%ofthereferencevoltage,theundervoltageprotectionistriggeredandthePGOODsignalgoeslow.After80µs,thecontrollerislatchedoffwithboththeupperandlowerMOSFETsturnedoff.Afterboththeundervoltageandovervoltageevents,thedeviceislatchedoff.NormaloperationcanberestoredonlybycyclingtheVCCpinvoltage.PowerTheTPS53211monitorstheoutputvoltagethroughtheVSEN.Duringstartup,thepowergoodsignaldelayafterthereferencebeginstoriseis1560clockcycles.Afterthisdelay,iftheoutputvoltageiswithin±9.5%ofthetargetvalue,PGOODsignalgoeshigh.Atsteadystate,iftheVSENvoltageiswithin113%and87%ofthereferencevoltage,thepowergoodsignalremainshigh.IfVSENvoltageisoutsideofthislimit,PGOODpinispulledlowbytheinternalopendrainoutput.ThePGOODoutputisanopendrainandrequiresanexternalpull-upresistor.TheTPS53211continuouslymonitorsthedietemperature.Ifthedietemperatureexceedsthethresholdvalue(140˚Ctypical),thedeviceshutsoff.Whenthedevicetemperaturelowersto40˚Cbelowtheover-temperaturethreshold,itrestartsandreturntonormaloperation.APPLICATIONThefollowingexampleillustratesthedesignprocessandcomponentselectionforasingleoutputsynchronousbuckconverterusingTPS53211.TheschematicofadesignexampleisshowninFigure5.ThespecificationsoftheconverterarelistedinTable1.Table1.SpecificationoftheSingleOutputSynchronousBuckTESTInputVOutputVVROutputIOUT=201%ofVOutputASwitchingEnableEnableGood89765ENPGOOD410PHASE11LGATE12 1Figure5.Typical12-VInputApplication

UDGOutputInductorDetermineaninductancevaluethatyieldsaripplecurrentofapproxima y20%to40%of umoutputcurrent.TheinductorripplecurrentisdeterminedbyEquation3: L

TheinductorrequiresalowDCRtoachievegoodefficiency,aswellasenoughroomabovepeakinductorcurrentbeforesaturation.OutputCapacitorTheoutputcapacitorselectionisdeterminedbyoutputrippleandtransientrequirement.WhenoperatinginCCM,theoutputripplehasthreecomponents:VRIPPLEVRIPPLE(C)VRIPPLE(ESR)8 8 VRIPPLE(ESR)IL(ripple)

VIN Whenaceramicoutputcapacitorischosen,theESLcomponentisusuallynegligible.Inthecasewhenmultipleoutputcapacitorsareused,thetotalESRandESLshouldbetheequivalentofthealloutputcapacitorsinparallel.WhenoperatinginDCM,theoutputrippleisdominatedbythecomponentdeterminedbycapacitance.ItalsovarieswithloadcurrentandcanbeexpressedasshowninEquation8.2 222 αistheDCMOn-Timecoefficientandcanbeexpressed

xxFigure6.DCMVOUTRipple

InputCapacitorDisthedutycycleandcanbeexpressed

D Tominimizetheripplecurrentdrawnfromtheinputsource,sufficientinputdecouplingcapacitorsshouldbecedclosetothedevice.Theceramiccapacitoris mendedduetotheinherentlowESRandlowESL.Theinputvoltageripplecanbecalculatedasbelowwhenthetotalinputcapacitanceisdetermined:

IOUTfSW OutputVoltageSettingResistorsTheoutputvoltageisprogrammedbythevoltage-dividerresistor,R1andR2showninFigure7.R1isconnectedbetweenFBpinandtheoutput,andR2isconnectedbetweentheFBpinandFBG.The mendedvalueforR1isbetween1kΩand5kΩ.DetermineR2usingEquation11. Compensation

TheTPS53211employsvoltagemodecontrol.Toeffectivelycompensationthepowerstageandensuresfasttransientresponse,TypeIIIcompensationistypicallyused.ThecontroltooutputtransferfunctioncanbedescribedinEquation 4

1sCOUT 1s OUT(ESRDCR)sL TheoutputLCfilterintroducesadoublepole,calculatedinEquationLfDPL2TheESRzeroofcanbecalculatedcalculatedinEquation

2ESR Figure7showstheconfigurationofTypeIIIcompensationandtypicalpoleandzerolocations.Equation15throughEquation17describethecompensatortransferfunctionandpolesandzerosoftheTypeIIInetwork.GEA sR(CC)1sCR1sR4C2C3 C2fZ2

12R41

VREF

UDGFigure7.TypeIIICompensationNetwork Figure8.TypeIIICompensationNetwork fP1 f

2

2

CC 2R4 C2C3 Thetwozeroscanbecednearthedoublepolefrequencytocanceltheresponsefromthedoublepole.OnepolecanbeusedtocancelESRzero,andtheothernon-zeropolecanbecedathalfswitchingfrequencytoattenuatethehighfrequencynoiseandswitchingripple.Suitablevaluescanbeselectedtoachieveacompromisebetweenhighphasemarginandfastresponse.Aphasemarginhigherthan45degreesisrequiredforstableoperation.PACKAGEOPTIONPACKAGINGOrderableStatusPackagePackageEconMSLPeakTemp&noSb/Br)CU&noSb/Br)CU(1)ThemarketingstatusvaluesaredefinedasACTIVE:Product mendedfornewLIFEBUY:TIhasannouncedthatthedevicewillbedis,andalifetime-buyperiodisinNRND: mendedfornewdesigns.Deviceisinproductiontosupportexistingcustomers,butTIdoes mendusingthispartinanewPREVIEW:Devicehasbeenannouncedbutisnotinproduction.SamplesmayormaynotbeOBSOLETE:TIhasdistheproductionofthe(2)Econ-Thennedeco-friendlyclassification:Pb-(RoHS),Pb-(RoHSExempt),orGreen(RoHS&noSb/Br)-pleasecheck informationandadditionalproductcontentdetails.TBD:ThePb-/Green nhasnotbeenPb-(RoHS):TI'sterms"Lead- "or"Pb-"meansemiconductorproductsthatarecompatiblewiththecurrentRoHSrequirementsforall6substances,includingtherequirementthatleadnotexceed0.1%byweightinhomogeneousmaterials.Wheredesignedtobesolderedathightemperatures,TIPb- productsaresuitableforuseinspecifiedlead-processes.Pb-(RoHSExempt):ThiscomponenthasaRoHSexemptionforeither1)lead-basedflip-chipsolderbumpsusedbetweenthedieandpackage,or2)lead-baseddieadhesiveusedbetweenthedieandleadframe.ThecomponentisotherwiseconsideredPb-(RoHScompatible)asdefinedabove.Green(RoHS&noSb/Br):TIdefines"Green"tomeanPb-(RoHScompatible),and ofBromine(Br)andAntimony(Sb)basedflameretardants(BrorSbdonotexceed0.1%byweightinhomogeneousmaterial)(3)MSL,PeakTemp.--TheMoistureSensitivityLevelratingaccordingtotheJEDECindustrystandardclassifications,andpeaksolderImportantInformationandDier:Theinformationprovidedon