TPS54331-Q1 - Texas Instruments

1 - %I - Load Current - ALV = VOV = 12 VIV = 18 VIV = 24 VIV = 28 VIV = 5 NOVEMBER20103-A,28-VINPUT,STEP-DOWNSWIFT DC/DCCONVERTERWITHEco-Mode CheckforSamples: tps54331 -Q11 FEATURESAPPLICATIONS ConsumerApplicationssuchasSet-Top2 QualifiedforAutomotiveApplicationsBoxes, CPEE quipment,LCDD isplays, ,andBatteryChargers IndustrialandCarAudioPowerSupplies Integrated80m HighSideMOSFETS upports 5-V,12-Vand24-VDistributedPowerSystemsup to3 AContinuousOutputCurrent HighEfficiencyatLightLoadswithPulseDESCR IPTIONS kippingEco-mode ControlTheTPS54331is a 28-V,3-Anon-synchronousbuck Fixed570kHzSwitchingFrequencyconverterth atintegratesalowRDS(on)highside Typical1mA ,apulseskippingEco-mode featureisautomatically ,the1mAshutdownsupply ProgrammableUVLOT hresholdcurrentallowsthedevicetobeusedin battery Cycle-by-CycleCurrentLimit,FrequencyFold compensationcalculationsandreducescompon entBackandThermalShutdownProtectioncount whileallowingtheuseofceramicoutput resistordividerprogramsthehysteresis SupportedbySwitcherPro ( )

2 Cyclecurrentlimitscheme,frequencyfoldbac kand ForSWIFT Documentation, ,standardwarranty,andusein ,Eco-mode,SwitcherPro, 2010, ,see:TPS54231 TPS54232 TPS54233 tps54331 TPS54332IO(Max) 28 VSwitchingFreq.(Typ)570kHz1000kHz285kHz5 70kHz1000kHzSwitchCurrentLimit(Min) ORDERINGINFORMATION(1)TJPACKAGE(2)ORDERA BLEPARTNUMBERTOP-SIDEMARKING 40 C to150 CSOIC DReelof2500 tps54331 QDRQ154331Q(1)Forthemostcurrentpackagean dorderinginformation,seethePackageOption Addendumattheendofthisdocument, (2)Packagedrawings,thermaldata, (1)overoperatingfree-airtemperaturerange (unlessotherwisenoted)VALUEUNITVIN (10nstransientfromgroundtonegativepeak) 5EN100mABOOT100mASourcecurrentVSENSE10mA PH9 AVIN9 ASinkcurrentCOMP100mASS200 Operatingjunctiontemperature 40to150 CStoragetemperature 65to150 C(1) ,andfunctionaloperationofthedeviceatthes eoranyotherconditionsbeyondthoseindicate dunderrecommendedoperatingconditionsis (HBM)1000 VESDE lectrostaticdischargeratingCharged-Devic eModel(CDM)1000 VMachineModel(MM)

3 100V2 SubmitDocumentationFeedbackCopyright 2010,TexasInstrumentsIncorporatedProduct FolderLink(s) NOVEMBER2010 PACKAGEDISSIPATIONRATINGS(1)(2)(3)THERMA LIMPEDANCEPSEUDOTHERMALIMPEDANCEPACKAGEJ UNCTIONTOAMBIENTJUNCTIONTOTOPSOIC8100 C/W5 C/W(1)Maximumpowerdissipationmaybelimite dbyovercurrentprotection(2)Powerratingat a specificambienttemperatureTAshouldbedete rminedwitha junctiontemperatureof150 C applicationsectionofthisdatasheetformore information.(3)Testboardconditions:(a)2 inchesx ,2 layers, (b)2-ouncecoppertraceslocatedonthetopand bottomofthePCB(c)6 thermalviaslocatedunderthedevicepackageR ECOMMENDEDOPERATINGCONDITIONS overoperatingfree-airtemperaturerange(un lessotherwisenoted)MINTYPMAXUNITO peratinginputvoltageon(VINpin) ,TA 40125 COperatingjunctiontemperature,TJ 40150 CELECTRICALCHARACTERISTICSTJ= 40 C to150 C,VIN= (unlessotherwisenoted)DESCRIPTIONTESTCON DITIONSMINTYPMAXUNITSUPPLYVOLTAGE(VINPIN ) 0V,VIN= 12V, 40 C to85 C14mAOperating nonswitchingsupplycurrentVSENSE= (ENPIN) 50mV-1mAInputcurrentEnablethreshold+ 3 V,VIN= OnresistanceBOOT-PH= 6 V,VIN= 12V80150 ERRORAMPLIFIERE rroramplifiertransconductance(gm) 2mA < ICOMP< 2mA,V(COMP)= 1 V92mmhosErroramplifierDCgain(1)VSENSE= (1)5 (COMP)

4 = 1 V,100mVoverdrive 7mASwitchcurrenttoCOMP transconductanceVIN= 12V12A/VSWITCHINGFREQUENCYS witchingFrequencyVIN= 12V,25 C456570684kHzMinimumcontrollableontimeVI N= 12V,25 C105130nsMaximumcontrollabledutyratio(1) BOOT-PH= 6 V90%93%(1)SpecifiedbydesignCopyright 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback3 ProductFolderLink(s): tps54331 -Q112345678 BOOTVINENSSPHGNDCOMPVSENSETPS54331-Q1 SLVSAB5 (continued)TJ= 40 C to150 C,VIN= (unlessotherwisenoted)DESCRIPTIONTESTCON DITIONSMINTYPMAXUNITPULSESKIPPINGECO-MOD E PulseskippingEco-mode switchcurrentthreshold160mACURRENTLIMITC urrentlimitthresholdVIN= CSLOWSTART(SSPIN)ChargecurrentV(SS)= (SS)= bootstrapcapacitoris thevoltageonthiscapacitorfallsbelowthemi nimumrequirement,thehigh-sideMOSFETis forcedtoswitchoffuntilthecapacitoris , , 2010,TexasInstrumentsIncorporatedProduct FolderLink(s).

5 TPS54331-Q1 ErrorAmplifierR QSBootChargeBootUVLOC urrentSenseOscillatorFrequencyShiftGateD riveLogicSlopeCompensationPWML atchPWMC omparatorECO-MODEM inimum Clamp V80 mW165 A/VSSS hutdownVSENSE1 Am3 Amgm = 92 A/VDC gain = 800 V/VBW = MHzm2 kW2 NOVEMBER2010 FUNCTIONALBLOCKDIAGRAMC opyright 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback5 ProductFolderLink(s): tps54331 -Q160657075 80859095100105110-50-250255075100125150T - Junction Temperature - CJRdson - On Resistance - mWVIN = 12 V012343813182328V - Input Voltage - VIIsd - Shutdown Current - AmEN = 0 VT = 150 CJT = 25 CJT = -40 CJ550555560565570575580585590-50-2502550 75100125150fsw - Oscillator Frequency - kHzT - Junction Temperature - CJVIN = 12 125150 Vref - Voltage Reference - VT - Junction Temperature - Controllable Duty Ratio - %T - Junction Temperature - CJVIN = 12 V100110120130140-50-250255075100125150 Tonmin - Minimum Controllable On Time - nsT - Junction Temperature - CJVIN = 12 V34563813182328V - Input Voltage - VICurrent Limit Threshold - AT = 150 CJT = 25 CJT = -40 Slow Start Charge Current - ASSmT - Junction Temperature - CJTPS54331-Q1 SLVSAB5 2010,TexasInstrumentsIncorporatedProduct FolderLink(s).

6 tps54331 -Q13813182328V - Output Voltage - VOV - Input Volatage - = 2 AOI = 3 AO3813182328051015202530V - Output Voltage - VOV - Input Voltage - VII = 2 AOI = 3 - Power Dissipation - WDT - Junction Temperature - NOVEMBER2010 TYPICALCHARACTERISTICS(continued) a 28-V,3-A,step-down(buck) ,thedeviceimplementsa constantfrequency, (UVLO) ,thepull-upcurrentprovidesa defaultconditionwhentheENpinis ,thesupplycurrentis 1mA monitoredbyanUVLO circuitandwillturnthehigh-sideMOSFET offwhenthevoltagefallsbelowa , ,theTPS54331entersa fixedfrequency, 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback7 ProductFolderLink(s) VVIN+-Ren1 Ren2 TPS543311 Am3 AmSTARTSTOPV- VRen1 =3 AmENSTARTENVRen2 =V- V+ 1 ARen1mTPS54331-Q1 SLVSAB5 lowerthan160mAtypically, WhenthedeviceisinEco-modeTM, Sincetheintegratedcurrentcomparatorcatch esthepeakinductorcurrentonly, (Vref)Thevoltagereferencesystemproducesa 2%initialaccuracyvoltagereference( )byscalingtheoutputofa (BOOT)TheTPS54331hasanintegratedbootregu latorandrequiresa ceramiccapacitorwithanX7 RorX5 Rgradedielectricis ,theTPS54331is designedtooperateat100% (VINUVLO) is recommendedtouseanexternalVINUVLO toaddHysteresisunlessVINis greaterthan(VOUT+ 2 V).

7 ToadjusttheVINUVLO withHysteresis,usetheexternalcircuitryco nnectedtotheENpinasshowninFigure12. ,anadditional3mA ofhysteresisis andEquation2 theinputstartthresholdvoltage,theVSTOPis theinputstopthresholdvoltageandtheVENis (1)(2)PROGRAMMABLESLOWSTARTUSINGSSPINIt ishighlyrecommendedtoprogramtheslowstart timeexternallybecausenoslowstarttimeisim plemented8 SubmitDocumentationFeedbackCopyright 2010,TexasInstrumentsIncorporatedProduct FolderLink(s): TPS54331-Q1 ( )( )( )( )SSrefSSSSCnFVVTms =IA s capacitor(CSS) ontheSSpintogroundimplementsa (10%to90%)is shownin Equation3 . TheVrefis andtheISScurrentis 2mA.(3) duringnormaloperation,theinputvoltagedro psbelowtheVINUVLO threshold,ortheENpinis ,ora thermalshutdowneventoccurs, ,theTPS54331addsa built-inslopecompensationwhichis a ,thetypicaldesignsforcommonapplicationsa relistedin , Softwaretool( ).

8 (ReferringtoSimplifiedSchematiconpage1)V INVOUTFswLoCoRO1RO2C2C1R3(V)(V)(kHz)(mH) (k )(k )(pF)(pF)(k ) ;whenthepeakinductorcurrentintersectsthe COMP pinvoltage, ,theerroramplifierrespondsbydrivingtheCO MP pinhigh, maximumclampinternally, 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback9 ProductFolderLink(s): TPS54331-Q1 TPS54331-Q1 SLVSAB5 potentialforovercurrentrunawayintheoutpu tinductorduringa dividedby8,4,2,and1 asthevoltagerampsfrom0 V shownin > VSENSE > VSENSE > VSENSEOVERVOLTAGETRANSIENTPROTECTIONTheT PS54331incorporatesanovervoltagetransien tprotection(OVTP) Vref, Vref, thejunctiontemperatureexceeds165 C, 2010,TexasInstrumentsIncorporatedProduct FolderLink(s) FVin 7 V 28 V " "F332 k# k#47 pF0#47 FVout VIout Max 3 k# k# k#1000 pF47 ,theSwitcherPro Softwaremaybeusedtogeneratea Softwareusesaniterativedesignprocedurean daccessesa comprehensivedatabaseofcomponentswhengen eratinga.

9 Inputvoltagerange Outputvoltage Inputripplevoltage Outputripplevoltage Outputcurrentrating OperatingfrequencyForthisdesignexample, V AOperatingFrequency570kHzSWITCHINGFREQUE NCYT heswitchingfrequencyfortheTPS54331is 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback11 ProductFolderLink(s): TPS54331-Q1 REFOUTREFR5VR6 =VV -OUTREFR5V = V+1R6 ()OUT(MAX)INOUT(MAX) =+ IESRCf D 2 OUT(MAX)CINII= TPS54331-Q1 SLVSAB5 externallyadjustableusinga , thisdividernetworkis givenbyEquation4 andEquation5:(4)(5) . SlightlyincreasingordecreasingR5canresul tin ,R4= andR = , resultingin a ,a smallervaluemaybeusedaslongasallotherreq uirementsaremet;however10mF hasbeenshowntoworkwellin a ,somebulkcapacitancemaybeneeded,especial lyif theTPS54331circuitisnotlocatedwithinabou t2 notcriticalbutshouldberatedtohandlethema ximuminputvoltageincludingripplevoltage, andshouldfiltertheoutputsothatinputrippl evoltageis (ESR)isapproximately2m , andthecurrentratingis 3 ,a capacitoris (6)WhereIOUT(MAX)is themaximumloadcurrent,fSWis theswitchingfrequency,CBULKis thebulkcapacitorvalueandESRMAXis ,thiscanbeapproximatedbyEquation7(7)Inth iscase, showninDesignParametersandis andtheripplecurrentcapacityisgreaterthan 3 A, is , ,a ,useEquation812 SubmitDocumentationFeedbackCopyright 2010,TexasInstrumentsIncorporatedProduct FolderLink(s).

10 TPS54331-Q1 ()OUT(MAX)IN(MAX)OUTMININ(MAX )INDOUTSWVVVL=VKIF - ()2 OUTIN(MAX)OUT2L(RMS)OUT(MAX)IN(MAX)OUTSW VVV1I= I+ - ()OUTIN(MAX)OUTL(PK) OUT(MAX)IN(MAX)OUTSWVVVI= I+ VLF - )2/(1max_min_COOOFRC =p + -=ESROSWLPPO PPRCFDIV4) ( NOVEMBER2010(8)KINDis a ,thisvalueisatthediscretionofthedesigner ;however, ,a valueashighasKIND= ,KIND= ,useKIND= ,a ,it is (9)andthepeakinductorcurrentcanbedetermi nedwithEquation10(10)Forthisdesign,theRM Sinductorcurrentis andthepeakinductorcurrentis a hasa , loweroutputvoltageripple, , ,ripplecurrentrating,andequivalentseries resistance(ESR). notcritical, ,it isdesirabletokeeptheclosedloopcrossoverf requencyatlessthan1 , , :(11)WhereROistheoutputloadimpedance(VO/ IO) desiredmaximumcrossoverof25kHztheminimum valuefortheoutputcapacitoris ; :(12)WhereNCis thenumberofoutputcapacitorsin 2010,TexasInstrumentsIncorporatedSubmitD ocumentationFeedback13 ProductFolderLink(s): TPS54331-Q1 () ()12 OUTIN(MAX)OUTCOUT(RMS)IN(MAX)OUTSWCV VV1I= V L F N - ggmREFDCOVVG=V ()POOOZV = 1/ 2 RCp ()Z1 ZZF = 1/ 2R Cp ()P1 ZPF = 1/ 2R Cp TPS54331-Q1 SLVSAB5 theinductorripplecurrenttimestheESRofthe outputfilter,sothemaximumspecifiedESRasl istedinthecapacitordatasheetis givenbyEquation13(13) givenbyEquation14.