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4.5Vto18VInput,3-ASYNCHRONOUSSTEPDOWNCONVERTER

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FEATURES

•

D-CAP2™ModeEnablesFastTransientResponse

LowOutputRippleandAllowsCeramicOutputCapacitor

WideVINInputVoltageRange:4.5Vto18VOutputVoltageRange:0.76Vto7.0V

HighlyEfficientIntegratedFETsOptimizedforLowerDutyCycleApplications

–100mΩ(HighSide)and74mΩ(LowSide)HighEfficiency,LessThan10μAatShutdownHighInitialBandgapReferenceAccuracyAdjustableSoftStartPre-BiasedSoftStart

650-kHzSwitchingFrequency(fSW)CycleByCycleOverCurrentLimit

DESCRIPTION

TheTPS54329isanadaptiveon-timeD-CAP2™modesynchronousbuckconverter.TheTPS54329enablessystemdesignerstocompletethesuiteofvariousendequipment’spowerbusregulatorswithacosteffective,lowcomponentcount,lowstandbycurrentsolution.ThemaincontrolloopfortheTPS54329usestheD-CAP2™modecontrolwhichprovidesafasttransientresponsewithnoexternalcompensationcomponents.TheTPS54329alsohasaproprietarycircuitthatenablesthedevicetoadopttobothlowequivalentseriesresistance(ESR)outputcapacitors,suchasPOSCAPorSP-CAP,andultra-lowESRceramiccapacitors.Thedeviceoperatesfrom4.5-Vto18-VVINinput.Theoutputvoltagecanbeprogrammedbetween0.76Vand7V.Thedevicealsofeaturesanadjustablesoftstarttime.TheTPS54329isavailableinthe8-pinDDApackage,anddesignedtooperatefrom–40°Cto85°C.

••••

••••••

APPLICATIONS

•

WideRangeofApplicationsforLowVoltageSystem

–DigitalTVPowerSupply

–HighDefinitionBlu-rayDisc™Players–NetworkingHomeTerminal–DigitalSetTopBox(STB)

VOUT(50 mV/div)

TPS54329DDAIOUT(1A/div)

100μs/div

G006

Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofTexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.

D-CAP2isatrademarkofTexasInstruments.

Blu-rayDiscisatrademarkofBlu-rayDiscAssociation.

Copyright©2011–2012,TexasInstrumentsIncorporated

PRODUCTIONDATAinformationiscurrentasofpublicationdate.ProductsconformtospecificationsperthetermsoftheTexasInstrumentsstandardwarranty.Productionprocessingdoesnotnecessarilyincludetestingofallparameters.

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ThisintegratedcircuitcanbedamagedbyESD.TexasInstrumentsrecommendsthatallintegratedcircuitsbehandledwithappropriateprecautions.Failuretoobserveproperhandlingandinstallationprocedurescancausedamage.

ESDdamagecanrangefromsubtleperformancedegradationtocompletedevicefailure.Precisionintegratedcircuitsmaybemoresusceptibletodamagebecauseverysmallparametricchangescouldcausethedevicenottomeetitspublishedspecifications.

ORDERINGINFORMATION(1)

TA

–40°Cto85°C(1)(2)(3)

PACKAGE(2)

DDA

(3)

ORDERABLEPARTNUMBER

TPS54329DDATPS54329DDAR

PIN8

TRANSPORTMEDIA

TubeTapeandReel

Forthemostcurrentpackageandorderinginformation,seethePackageOptionAddendumattheendofthisdocument,orseetheTIwebsiteatwww.ti.com.

Packagedrawings,thermaldata,andsymbolizationareavailableatwww.ti.com/packaging.AllpackageoptionshaveCuNIPDAUlead/ballfinish.

ABSOLUTEMAXIMUMRATINGS

overoperatingfree-airtemperaturerange(unlessotherwisenoted)

(1)

VALUE

MIN

VIN,ENVBST

VBST(10nstransient)

Inputvoltagerange

VBST(vsSW)VFB,SSSW

SW(10nstransient)

Outputvoltagerange

VREG5GND

HumanBodyModel(HBM)ChargedDeviceModel(CDM)

–40–55–0.3–0.3–0.3–0.3–0.3–2–3–0.3–0.3–0.2

MAX2026286.56.520226.50.30.22500150150

UNITVVVVVVVVVVkVV°C°C

VoltagefromGNDtothermalpad,VdiffElectrostaticdischarge

Operatingjunctiontemperature,TJStoragetemperature,Tstg(1)

Stressesbeyondthoselistedunderabsolutemaximumratingsmaycausepermanentdamagetothedevice.Thesearestressratingsonly,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedunderrecommendedoperatingconditionsisnotimplied.Exposuretoabsolute-maximum-ratedconditionsforextendedperiodsmayaffectdevicereliability.

THERMALINFORMATION

THERMALMETRIC

θJAθJCtopθJBψJTψJBθJCbot

Junction-to-ambientthermalresistanceJunction-to-case(top)thermalresistanceJunction-to-boardthermalresistanceJunction-to-topcharacterizationparameterJunction-to-boardcharacterizationparameterJunction-to-case(bottom)thermalresistance

TPS54329DDA(8PINS)

42.150.931.8513.57.1

°C/WUNITS

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RECOMMENDEDOPERATINGCONDITIONS

overoperatingfree-airtemperaturerange(unlessotherwisenoted)

MIN

VIN

Supplyinputvoltagerange

VBST

VBST(10nstransient)VBST(vsSW)SS

VI

Inputvoltagerange

ENVFBSW

SW(10nstransient)GND

VOIOTATJ

OutputvoltagerangeOutputCurrentrange

Operatingfree-airtemperatureOperatingjunctiontemperature

VREG5IVREG5

4.5–0.1-0.1–0.1–0.1–0.1–0.1–1.8–3–0.1–0.10–40–40

MAX1824275.75.7185.518210.15.71085150

VmA°C°CVUNITV

ELECTRICALCHARACTERISTICS

overoperatingfree-airtemperaturerange,VIN=12V(unlessotherwisenoted)

PARAMETER

SUPPLYCURRENTIVINIVINSDNVENHVENLRENVFBTHIVFB

Operating-non-switchingsupplycurrentShutdownsupplycurrentENhigh-levelinputvoltageENlow-levelinputvoltageENpinresistancetoGNDVFBthresholdvoltageVFBinputcurrent

VINcurrent,TA=25°C,EN=5V,VFB=0.8V

VINcurrent,TA=25°C,EN=0VENENVEN=12V

TA=25°C,VO=1.05V,continuousmodeVFB=0.8V,TA=25°CTA=25°C,6.0VVIN=6V,VREG5=4.0V,TA=25°C(1)25°C,VBST-SW=5.5V(1)25°C(1)

Lout=1.5μH(1)

3.5220749

4407650

1.6

0.45880781±0.1

8004.3

120010

μAμAVVkΩmVμA

TESTCONDITIONS

MIN

TYP

MAX

UNIT

LOGICTHRESHOLD

VFBVOLTAGEANDDISCHARGERESISTANCE

VREG5OUTPUTVVREG5IVREG5MOSFETRDS(on)hRDS(on)lIocl(1)

HighsideswitchresistanceLowsideswitchresistanceCurrentlimit

Notproductiontested.

100744.2

5.7

mΩmΩA

VREG5outputvoltageOutputcurrent

5.560

VmA

CURRENTLIMIT

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ELECTRICALCHARACTERISTICS(continued)

overoperatingfree-airtemperaturerange,VIN=12V(unlessotherwisenoted)

PARAMETER

THERMALSHUTDOWNTSDN

Thermalshutdownthreshold

ShutdowntemperatureHysteresis

(2)

(2)

TESTCONDITIONSMINTYP16535150260

MAXUNIT

°C

ON-TIMETIMERCONTROLtONtOFF(MIN)ISSCISSDUVLOUVLO

UVLOthreshold

WakeupVREG5voltageHysteresisVREG5voltage

3.750.33

V

Ontime

MinimumofftimeSSchargecurrentSSdischargecurrent

VIN=12V,VO=1.05VTA=25°C,VFB=0.7V(2)VSS=1VVSS=0.5V

4.20.1

nsns

7.8

μAmA

SOFTSTART

6.00.2

(2)Notproductiontested.

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DEVICEINFORMATION

DDAPACKAGE(TOPVIEW)

1VBSTTPS54329DDA(HSOP8)SS82VINEN73SWPower PADVREG5GNDVFB5PINFUNCTIONS

PIN

NAMEVBSTVINSWGNDVFBVREG5ENSS

ExposedThermalPad

NO.12345678Backside

DESCRIPTION

Supplyinputforthehigh-sideFETgatedrivecircuit.Connect0.1µFcapacitorbetweenVBSTandSWpins.AninternaldiodeisconnectedbetweenVREG5andVBST.Inputvoltagesupplypin.

Switchnodeconnectionbetweenhigh-sideNFETandlow-sideNFET.

Groundpin.Powergroundreturnforswitchingcircuit.ConnectsensitiveSSandVFBreturnstoGNDatasinglepoint.

Converterfeedbackinput.Connecttooutputvoltagewithfeedbackresistordivider.

5.5Vpowersupplyoutput.Acapacitor(typical0.47µF)shouldbeconnectedtoGND.VREG5isnotactivewhenENislow.

Enableinputcontrol.ENisactivehighandmustbepulleduptoenablethedevice.Soft-startcontrol.AnexternalcapacitorshouldbeconnectedtoGND.

Thermalpadofthepackage.Mustbesolderedtoachieveappropriatedissipation.MustbeconnectedtoGND.

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FUNCTIONALBLOCKDIAGRAM

EN7ENLogic2VINVINVREG5RefSSVFB5++PWMControl Logic1VBST1 shotSW3VO-XCONONVREG5VREG5SGNDSSPGND6CeramicCapacitor8SoftstartSS4GNDSGND+OCP-VINSWPGNDVREG5UVLOUVLOTSDProtectionLogicREFRef6

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OVERVIEW

TheTPS54329isa3-Asynchronousstep-down(buck)converterwithtwointegratedN-channelMOSFETs.ItoperatesusingD-CAP2™modecontrol.ThefasttransientresponseofD-CAP2™controlreducestheoutputcapacitancerequiredtomeetaspecificlevelofperformance.ProprietaryinternalcircuitryallowstheuseoflowESRoutputcapacitorsincludingceramicandspecialpolymertypes.

DETAILEDDESCRIPTION

PWMOperation

ThemaincontrolloopoftheTPS54329isanadaptiveon-timepulsewidthmodulation(PWM)controllerthatsupportsaproprietaryD-CAP2™modecontrol.D-CAP2™modecontrolcombinesconstanton-timecontrolwithaninternalcompensationcircuitforpseudo-fixedfrequencyandlowexternalcomponentcountconfigurationwithbothlowESRandceramicoutputcapacitors.Itisstableevenwithvirtuallynorippleattheoutput.

Atthebeginningofeachcycle,thehigh-sideMOSFETisturnedon.ThisMOSFETisturnedoffafterinternaloneshottimerexpires.Thisoneshotissetbytheconverterinputvoltage,VIN,andtheoutputvoltage,VO,tomaintainapseudo-fixedfrequencyovertheinputvoltagerange,henceitiscalledadaptiveon-timecontrol.Theone-shottimerisresetandthehigh-sideMOSFETisturnedonagainwhenthefeedbackvoltagefallsbelowthereferencevoltage.Aninternalrampisaddedtoreferencevoltagetosimulateoutputripple,eliminatingtheneedforESRinducedoutputripplefromD-CAP2™modecontrol.PWMFrequencyandAdaptiveOn-TimeControl

TPS54329usesanadaptiveon-timecontrolschemeanddoesnothaveadedicatedonboardoscillator.TheTPS54329runswithapseudo-constantfrequencyof650kHzbyusingtheinputvoltageandoutputvoltagetosettheon-timeone-shottimer.Theon-timeisinverselyproportionaltotheinputvoltageandproportionaltotheoutputvoltage,therefore,whenthedutyratioisVOUT/VIN,thefrequencyisconstant.SoftStartandPre-BiasedSoftStart

Thesoftstartfunctionisadjustable.WhentheENpinbecomeshigh,6μAcurrentbeginschargingthecapacitorwhichisconnectedfromtheSSpintoGND.Smoothcontroloftheoutputvoltageismaintainedduringstartup.TheequationfortheslowstarttimeisshowninEquation1.VFBvoltageis0.765VandSSpinsourcecurrentis6μA.

tSS(ms)=

CSS(nF)xVREF´1.1

I(mA)SS

=

CSS(nF)x0.765´1.1

6

(1)

TheTPS54329containsauniquecircuittopreventcurrentfrombeingpulledfromtheoutputduringstartupiftheoutputispre-biased.Whenthesoft-startcommandsavoltagehigherthanthepre-biaslevel(internalsoftstartbecomesgreaterthanfeedbackvoltageVFB),thecontrollerslowlyactivatessynchronousrectificationbystartingthefirstlowsideFETgatedriverpulseswithanarrowon-time.Itthenincrementsthaton-timeonacycle-by-cyclebasisuntilitcoincideswiththetimedictatedby(1-D),whereDisthedutycycleoftheconverter.Thisschemepreventstheinitialsinkingofthepre-biasoutput,andensurethattheoutvoltage(VO)startsandrampsupsmoothlyintoregulationandthecontrolloopisgiventimetotransitionfrompre-biasedstart-uptonormalmodeoperation.CurrentProtection

Theoutputovercurrentprotection(OCP)isimplementedusingacycle-by-cyclevalleydetectcontrolcircuit.Theswitchcurrentismonitoredbymeasuringthelow-sideFETswitchvoltagebetweentheSWpinandGND.Thisvoltageisproportionaltotheswitchcurrent.Toimproveaccuracy,thevoltagesensingistemperaturecompensated.

Duringtheontimeofthehigh-sideFETswitch,theswitchcurrentincreasesatalinearratedeterminedbyVin,Vout,theon-timeandtheoutputinductorvalue.Duringtheontimeofthelow-sideFETswitch,thiscurrentdecreaseslinearly.TheaveragevalueoftheswitchcurrentistheloadcurrentIOUT.TheTPS54329constantlymonitorsthelow-sideFETswitchvoltage,whichisproportionaltotheswitchcurrent,duringthelow-sideon-time.Ifthemeasuredvoltageisabovethevoltageproportionaltothecurrentlimit,aninternalcounterisincrementedpereachSWcycleandtheconvertermaintainsthelow-sideswitchonuntilthemeasuredvoltageisbelowthevoltagecorrespondingtothecurrentlimitatwhichtimetheswitchingcycleisterminatedandanewswitching

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cyclebegins.Insubsequentswitchingcycles,theon-timeissettoafixedvalueandthecurrentismonitoredinthesamemanner.Iftheovercurrentconditionexistsfor7consecutiveswitchingcycles,theinternalOCLthresholdissettoalowerlevel,reducingtheavailableoutputcurrent.WhenaswitchingcycleoccurswheretheswitchcurrentisnotabovethelowerOCLthreshold,thecounterisresetandtheOCLlimitisreturnedtothehighervalue.

Therearesomeimportantconsiderationsforthistypeofover-currentprotection.Theloadcurrentonehalfofthepeak-to-peakinductorcurrenthigherthantheover-currentthreshold.Alsowhenthecurrentisbeinglimited,theoutputvoltagetendstofallasthedemandedloadcurrentmaybehigherthanthecurrentavailablefromtheconverter.Thismaycausetheoutputvoltagetofall.Whentheovercurrentconditionisremoved,theoutputvoltagewillreturntotheregulatedvalue.Thisprotectionisnon-latching.UVLOProtection

Undervoltagelockoutprotection(UVLO)monitorsthevoltageoftheVREG5pin.WhentheVREG5voltageislowerthanUVLOthresholdvoltage,theTPS54329isshutoff.Thisisprotectionisnon-latching.ThermalShutdown

TPS54329monitorsthetemperatureofitself.Ifthetemperatureexceedsthethresholdvalue(typically165°C),thedeviceisshutoff.Thisisnon-latchprotection.

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TYPICALCHARACTERISTICS

VIN=12V,TA=25°C(unlessotherwisenoted).

1200

VIN = 12 V1000

Shutdown Current (µA)Supply Current (µA)8006004002000−501614121082

050100Junction Temperature (°C)

150G001

VIN = 12 V0−50050100Junction Temperature (°C)

150G002

Figure1.VINCURRENTvsJUNCTIONTEMPERATURE

Figure2.VINSHUTDOWNCURRENTvs

JUNCTIONTEMPERATURE

1.07

5045EN Input Current (µA)40353025201510500510EN Input Voltage (V)

1520G003

VIN = 18 V1.06

L = CLF7045Output Voltage (V)1.05

1.04

VIN = 5 VVIN = 12 VVIN = 18 V0.51.01.52.0Output Current (A)

2.53.0G004

1.03

0.0Figure3.ENCURRENTvsENVOLTAGE

1.07

Figure4.1.05-VOUTPUTVOLTAGEvsOUTPUTCURRENT

VOUT(50 mV/div)

Output Voltage (V)1.06

IOUT(1A/div)

1.05

1.04

IOUT = 0 AIOUT = 1 A1.03

0510Input Voltage (V)

1520G005

100μs/div

G006

Figure5.1.05-VOUTPUTVOLTAGEvsINPUTVOLTAGE

Figure6.1.05-V,50-mAto2-ALOADTRANSIENT

RESPONSE

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TYPICALCHARACTERISTICS

VIN=12V,TA=25°C(unlessotherwisenoted).

100

L = CLF7045EN (10 V/div)

90Efficiency (%)80706050400.0G007

VREG5 (5 V/div)

VOUT(0.5 V/div)

VOUT = 1.8 VVOUT = 2.5 VVOUT = 3.3 V0.51.01.52.0Output Current (A)2.53.0G008 400 µs/div

Figure7.START-UPWAVEFORM

900850Switching Frequency (kHz)800750700650600550500450400

0VOUT = 1.05 VVOUT = 1.2 VVOUT = 1.5 VVOUT = 1.8 VVOUT = 2.5 VVOUT = 3.3 VVOUT = 5.0 V510Input Voltage (V)

1520G009

Figure8.EFFICIENCYvsOUTPUTCURRENT

900

IOUT = 1 ASwitching Frequency (kHz)850800750700650600550500450400

0VIN = 12 VVOUT = 1.05 VVOUT = 1.8 VVOUT = 3.3 V0122Output Current (A)

23G010

Figure9.SWITCHINGFREQUENCYvsINPUTVOLTAGE

Figure10.SWITCHINGFREQUENCYvs

OUTPUTCURRENT

VOUT= 1.05 V

0.780

IO = 1 A0.775VFB Voltage (V)0.7700.7650.7600.7550.750

−40VOUT(10 mV/div)

SW (5 V/div)

−20020406080Junction Temperature (°C)

100120G011

400 ns/div

G012

Figure11.VfbVOLTAGEvsJUNCTIONTEMPERATURE

Figure12.VOLTAGERIPPLEATOUTPUT(IO=3A)

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TYPICALCHARACTERISTICS

VIN=12V,TA=25°C(unlessotherwisenoted).

VOUT= 1.05 V

VIN(50 mV/div)

SW (5 V/div)

400 ns/div

G013

Figure13.VOLTAGERIPPLEATINPUT(IO=3A)

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DESIGNGUIDE

StepByStepDesignProcedureTo•••••

beginthedesignprocess,youmustknowafewapplicationparameters:InputvoltagerangeOutputvoltageOutputcurrent

OutputvoltagerippleInputvoltageripple

U1TPS54329DDAFigure14.Showstheschematicdiagramforthisdesignexample.

OutputVoltageResistorsSelection

TheoutputvoltageissetwitharesistordividerfromtheoutputnodetotheVFBpin.Itisrecommendedtouse1%toleranceorbetterdividerresistors.StartbyusingEquation2tocalculateVOUT.

Toimproveefficiencyatverylightloadsconsiderusinglargervalueresistors,toohighofresistancewillbemoresusceptibletonoiseandvoltageerrorsfromtheVFBinputcurrentwillbemorenoticeable.

V=0.765xOUT

æöR1÷ç1+÷ççèøR2÷

(2)

OutputFilterSelection

TheoutputfilterusedwiththeTPS54329isanLCcircuit.ThisLCfilterhasdoublepoleat:

F=

P2pL1OUTxCOUT(3)

Atlowfrequencies,theoverallloopgainissetbytheoutputset-pointresistordividernetworkandtheinternalgainoftheTPS54329.Thelowfrequencyphaseis180degrees.Attheoutputfilterpolefrequency,thegainrollsoffata–40dBperdecaderateandthephasedropsrapidly.D-CAP2™introducesahighfrequencyzerothatreducesthegainrolloffto–20dBperdecadeandincreasesthephaseto90degreesonedecadeabovethezerofrequency.TheinductorandcapacitorselectedfortheoutputfiltermustbeselectedsothatthedoublepoleofEquation3islocatedbelowthehighfrequencyzerobutcloseenoughthatthephaseboostprovidedbethehighfrequencyzeroprovidesadequatephasemarginforastablecircuit.TomeetthisrequirementusethevaluesrecommendedinTable1

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Table1.RecommendedComponentValues

OutputVoltage(V)

11.051.21.51.82.53.356.5

(1)

Optional

R1(kΩ)6.818.2512.721.530.149.973.2124165

R2(kΩ)22.122.122.122.122.122.122.122.122.1

5-225-225-225-225-22C4(pF)(1)

L1(µH)1.51.51.51.52.22.22.23.33.3

C8+C9+C10(µF)

20-6820-6820-6820-6820-6820-6820-6820-6820-68

SincetheDCgainisdependentontheoutputvoltage,therequiredinductorvaluewillincreaseastheoutputvoltageincreases.Forhigheroutputvoltagesatorabove1.8V,additionalphaseboostcanbeachievedbyaddingafeedforwardcapacitor(C4)inparallelwithR1

Theinductorpeak-to-peakripplecurrent,peakcurrentandRMScurrentarecalculatedusingEquation4,Equation5andEquation6.TheinductorsaturationcurrentratingmustbegreaterthanthecalculatedpeakcurrentandtheRMSorheatingcurrentratingmustbegreaterthanthecalculatedRMScurrent.Use650kHzforfSW.

MakesurethechoseninductorisratedforthepeakcurrentofEquation5andtheRMScurrentofEquation6.

-VOUTVVIN(max)OUTI=x

IPPVLxfIN(max)OSW

I=I+IpeakO=I

Lo(RMS)

I(4)(5)(6)

Ilpp2

12+IIPPO122Forthisdesignexample,thecalculatedpeakcurrentis3.49AandthecalculatedRMScurrentis3.01A.The

inductorusedisaTDKCLF7045T-1R5Mwithapeakcurrentratingof7.3AandanRMScurrentratingof4.9A.ThecapacitorvalueandESRdeterminestheamountofoutputvoltageripple.TheTPS54329isintendedforusewithceramicorotherlowESRcapacitors.Recommendedvaluesrangefrom20µFto68µF.UseEquation7todeterminetherequiredRMScurrentratingfortheoutputcapacitor.

I

Co(RMS)

=

VOUTx(VIN-VOUT)12xVINxLOxfSW(7)

ForthisdesignthreeTDKC3216X5R0J106M10µFoutputcapacitorsareused.ThetypicalESRis2mΩeach.ThecalculatedRMScurrentis0.284Aandeachoutputcapacitorisratedfor4A.InputCapacitorSelection

TheTPS54229requiresaninputdecouplingcapacitorandabulkcapacitorisneededdependingontheapplication.Aceramiccapacitorover10μFisrecommendedforthedecouplingcapacitor.Anadditional0.1µFcapacitor(C3)isrequiredtoprovideadditionalhighfrequencyfilteringandinsureaccuratecurrentlimitoperation.ThiscapacitormustbeplacedasclosetotheICpins2(VIN)and4(GND)aspossible.Thecapacitorvoltageratingneedstobegreaterthanthemaximuminputvoltage.BootstrapCapacitorSelection

A0.1µF.ceramiccapacitormustbeconnectedbetweentheVBSTtoSWpinforproperoperation.Itisrecommendedtouseaceramiccapacitor.

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VREG5CapacitorSelection

A0.47µF.ceramiccapacitormustbeconnectedbetweentheVREG5toGNDpinforproperoperation.Itisrecommendedtouseaceramiccapacitor.

THERMALINFORMATION

This8-pinDDApackageincorporatesanexposedthermalpadthatisdesignedtobedirectlytoanexternalheartsick.Thethermalpadmustbesoldereddirectlytotheprintedboard(PCB).Aftersoldering,thePCBcanbeusedasaheartsick.Inaddition,throughtheuseofthermalvias,thethermalpadcanbeattacheddirectlytotheappropriatecopperplaneshownintheelectricalschematicforthedevice,oralternatively,canbeattachedtoaspecialheartsickstructuredesignedintothePCB.Thisdesignoptimizestheheattransferfromtheintegratedcircuit(IC).

Foradditionalinformationontheexposedthermalpadandhowtousetheadvantageofitsheatdissipatingabilities,refertoTechnicalBrief,PowerPAD™ThermallyEnhancedPackage,TexasInstrumentsLiteratureNo.SLMA002andApplicationBrief,PowerPAD™MadeEasy,TexasInstrumentsLiteratureNo.SLMA004.Theexposedthermalpaddimensionsforthispackageareshowninthefollowingillustration.

Figure15.ThermalPadDimensions(TopView)

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LAYOUTCONSIDERATIONS

1.Keeptheinputswitchingcurrentloopassmallaspossible.

2.KeeptheSWnodeasphysicallysmallandshortaspossibletominimizeparasiticcapacitanceandinductanceandtominimizeradiatedemissions.Kelvinconnectionsshouldbebroughtfromtheoutputtothefeedbackpinofthedevice.

3.Keepanalogandnon-switchingcomponentsawayfromswitchingcomponents.4.Makeasinglepointconnectionfromthesignalgroundtopowerground.5.Donotallowswitchingcurrenttoflowunderthedevice.6.KeepthepatternlinesforVINandPGNDbroad.

7.ExposedpadofdevicemustbeconnectedtoPGNDwithsolder.

8.VREG5capacitorshouldbeplacednearthedevice,andconnectedPGND.9.OutputcapacitorshouldbeconnectedtoabroadpatternofthePGND.

10.Voltagefeedbackloopshouldbeasshortaspossible,andpreferablywithgroundshield.

11.LowerresistorofthevoltagedividerwhichisconnectedtotheVFBpinshouldbetiedtoanaloggroundtrace.

12.ProvidingsufficientviasforVIN,SWandPGNDconnection.

13.VINinputbypasscapacitorandVINhighfrequencybypasscapacitormustbeplacedasnearaspossibletothedevice.

14.Performancebasedonfourlayerprintedcircuitboard.

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VIAto Power Ground Plane

VINVIAto SW Copper Pour on Bottomor Internal LayerVINHIGH FREQENCYBYPASSCAPACITORBOOSTCAPACITORANALOGGROUNDTRACEVININPUTBYPASSCAPACITORVBSTVINSWGNDSSENVREG5VFBBIASCAPSLOWSTARTCAPTO ENABLECONTROLPOWERGROUNDSW node copper pourarea on internal orbottom layerOUTPUTINDUCTOREXPOSEDTHERMALPADAREAFEEDBACKRESISTORSPOWERGROUNDConnection toPOWER GROUNDon internal orbottom layerVOUTOUTPUTFILTERCAPACITORFigure16.PCBLayout

16

ProductFolderLink(s):TPS54329

Copyright©2011–2012,TexasInstrumentsIncorporated

TPS54329

www.ti.com

SLVSAZ6A–SEPTEMBER2011–REVISEDMARCH2012

REVISIONHISTORY

ChangesfromOriginal(September2011)toRevisionA••••••

Page

Removed(SWIFT™)fromthedatasheettitle.....................................................................................................................1DeletedfromELECTRICALCHARACTERISTICStable,VLN5andVLD5,deletedVVREG5MINandMAXvalues..................3AddedinELECTRICALCHARACTERISTICStable,IVREG5,RDS(on)h,andRDS(on)lfootnotereferences................................3AddedtOFF(MIN)footnotereferenceanddeletedMAXvalue..................................................................................................4DeletedfromELECTRICALCHARARACTERISTICS,UVLOMINandMAXvalues...........................................................4AddedTYPICALCHARACTERISTICSCondition................................................................................................................9

Copyright©2011–2012,TexasInstrumentsIncorporated17

ProductFolderLink(s):TPS54329

PACKAGE OPTION ADDENDUM

www.ti.com

18-May-2012

PACKAGING INFORMATION

Orderable DeviceTPS54329DDATPS54329DDAR

(1)

Status

(1)

Package TypePackage

DrawingSO PowerPADSO PowerPAD

DDADDA

Pins88

Package Qty

752500

Eco Plan

(2)

Lead/Ball Finish

MSL Peak Temp

(3)

Samples(Requires Login)

ACTIVEACTIVE

Green (RoHS& no Sb/Br)Green (RoHS& no Sb/Br)

CU NIPDAUAGLevel-2-260C-1 YEAR

Call TI

Level-2-260C-1 YEAR

The marketing status values are defined as follows:ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.PREVIEW: Device has been announced but is not in production. Samples may or may not be available.OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availabilityinformation and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms \"Lead-Free\" or \"Pb-Free\" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement thatlead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used betweenthe die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines \"Green\" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weightin homogeneous material)

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on informationprovided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken andcontinues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1

PACKAGEMATERIALSINFORMATION

www.ti.com

5-May-2012

TAPEANDREELINFORMATION

*Alldimensionsarenominal

Device

PackagePackagePinsTypeDrawingSOPower PAD

DDA

8

SPQ

ReelReelA0DiameterWidth(mm)(mm)W1(mm)330.0

12.8

6.4

B0(mm)5.2

K0(mm)2.1

P1(mm)8.0

WPin1(mm)Quadrant12.0

Q1

TPS54329DDAR2500

PackMaterials-Page1

PACKAGEMATERIALSINFORMATION

www.ti.com

5-May-2012

*Alldimensionsarenominal

DeviceTPS54329DDAR

PackageTypeSOPowerPAD

PackageDrawing

DDA

Pins8

SPQ2500

Length(mm)

366.0

Width(mm)3.0

Height(mm)

50.0

PackMaterials-Page2

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