TPS71202资料

Actual Size(3 mm x 3 mm)

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TPS71202,TPS71219TPS71229,TPS71247TPS71256,TPS71257

SBVS049B–MAY2004–REVISEDMARCH2005

Dual250mAOutput,UltraLowNoise,HighPSRR,

Low-DropoutLinearRegulator

FEATURES

•••••••••••

Dual250mAHigh-PerformanceRFLDOsAvailableinFixedandAdjustableVoltageOptions(1.2Vto5.5V)HighPSRR:65dBat10kHzUltraLowNoise:32µVrmsFastStart-UpTime:60µs

Stablewith2.2µFCeramicCapacitorExcellentLoad/LineTransientResponse

VeryLowDropoutVoltage:125mVat250mAIndependentEnablePins

ThermalShutdownandIndependentCurrentLimit

AvailableinThermally-EnhancedSONPackage:3mmx3mmx1mm

DESCRIPTION

TheTPS712xxfamilyoflow-dropout(LDO)voltageregulatorsistailoredtonoise-sensitiveandRFappli-cations.Theseproductsfeaturedual250mALDOswithultralownoise,highpower-supplyrejectionratio(PSRR),andfasttransientandstart-upresponse.Eachregulatoroutputisstablewithlow-cost2.2µFceramicoutputcapacitorsandfeaturesverylowdropoutvoltages(125mVtypicalat250mA).Eachregulatorachievesfaststart-uptimes(approximately60µswitha0.001µFbypasscapacitor)whileconsumingverylowquiescentcurrent(300µAtypicalwithbothoutputsenabled).Whenthedeviceisplacedinstandbymode,thesupplycurrentisre-ducedtolessthan0.3µAtypical.Eachregulatorexhibitsapproximately32µVrmsofoutputvoltagenoisewithVOUT=2.8Vanda0.01µFnoisereduction(NR)capacitor.Applicationswithanalogcomponentsthatarenoise-sensitive,suchasport-ableRFelectronics,willbenefitfromhighPSRR,lownoise,andfastlineandloadtransientfeatures.TheTPS712familyisofferedinathin3mmx3mmSONpackageandisfullyspecifiedfrom-40°Cto+125°C(TJ).

APPLICATIONS

•••••

CellularandCordlessPhonesWirelessPDA/HandheldProductsPCMCIA/WirelessLANApplications

DigitalCamera/Camcorder/InternetAudioDSP/FPGA/ASIC/ControllersandProcessors

PSRR(RIPPLEREJECTION)vsFREQUENCY

8070

DRC PACKAGE3mm x 3mm SON(TOP VIEW)IN1NC2OUT13OUT24GND510EN19FB1/NC8EN27FB2/NC6NR

60PSRR(dB)5040302010010

VOUT=2.8VCOUT=2.2µFCNR=0.01µF100

1k

10k

100k

1M

10M

IOUT=1mAIOUT=250mAFrequency(Hz)

Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsofTexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.

PRODUCTIONDATAinformationiscurrentasofpublicationdate.ProductsconformtospecificationsperthetermsoftheTexasInstrumentsstandardwarranty.Productionprocessingdoesnotnecessarilyincludetestingofallparameters.

Copyright©2004–2005,TexasInstrumentsIncorporated

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ThisintegratedcircuitcanbedamagedbyESD.TexasInstrumentsrecommendsthatallintegratedcircuitsbehandledwithappropriateprecautions.Failuretoobserveproperhandlingandinstallationprocedurescancausedamage.

ESDdamagecanrangefromsubtleperformancedegradationtocompletedevicefailure.Precisionintegratedcircuitsmaybemoresusceptibletodamagebecauseverysmallparametricchangescouldcausethedevicenottomeetitspublishedspecifications.

ORDERINGINFORMATION(1)

VOLTAGE(TJ)PRODUCTTPS71202TPS71219TPS71229TPS71247TPS71256TPS71257(1)

VOUT1Adjustable1.8V2.8V1.8V2.8V2.85VVOUT2AdjustableAdjustableAdjustable2.85V2.8V2.85VPACKAGE-LEAD(DESIGNATOR)SON-10(DRC)SON-10(DRC)SON-10(DRC)SON-10(DRC)SON-10(DRC)SON-10(DRC)SPECIFIEDTEMPERATURERANGE(TJ)-40°Cto+125°C-40°Cto+125°C-40°Cto+125°C-40°Cto+125°C-40°Cto+125°C-40°Cto+125°CPACKAGEMARKINGARQARWARUARSARVARTORDERINGNUMBERTPS71202DRCTTPS71202DRCRTPS71219DRCTTPS71219DRCRTPS71229DRCTTPS71229DRCRTPS71247DRCTTPS71247DRCRTPS71256DRCTTPS71256DRCRTPS71257DRCTTPS71257DRCRTRANSPORTMEDIA,QUANTITYTapeandReel,250TapeandReel,3000TapeandReel,250TapeandReel,3000TapeandReel,250TapeandReel,3000TapeandReel,250TapeandReel,3000TapeandReel,250TapeandReel,3000TapeandReel,250TapeandReel,3000Forthemostcurrentpackageandorderinginformation,seethePackageOrderingAddendumlocatedattheendofthisdatasheet.

ABSOLUTEMAXIMUMRATINGS

overoperatingjunctiontemperaturerangeunlessotherwisenoted(1)

TPS712xx

VINrangeVEN1,VEN2rangeVOUTrangePeakoutputcurrentOutputshort-circuitdurationContinuoustotalpowerdissipationJunctiontemperaturerange,TJStoragetemperaturerangeESDrating,HBMESDrating,CDM(1)

-0.3to6.0-0.3toVIN+0.3-0.3to6.0Internallylimited

Indefinite

SeeDissipationRatingsTable-40to+150-65to+150

2500

°C°CkVVUNITVVV

Stressesbeyondthoselistedunderabsolutemaximumratingsmaycausepermanentdamagetothedevice.Thesearestressratingsonly,andfunctionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedundertheElectricalCharacteristicsisnotimplied.Exposuretoabsolutemaximumratedconditionsforextendedperiodsmayaffectdevicereliability.

POWERDISSIPATIONRATINGS

BOARDHigh-K(1)(1)

PACKAGEDRC

RθJC48

RθJA52

DERATINGFACTORABOVETA=25°C

19mW/°C

TA≤25°CPOWERRATING

1.92W

TA=70°CPOWERRATING

1.06W

TA=85°CPOWERRATING

0.77W

TheJEDECHigh-K(2s2p)boarddesignusedtoderivethisdatawasa3inchx3inch,multilayerboardwith1-ounceinternalpowerandgroundplanesand2-ouncecoppertracesonthetopandbottomoftheboard.

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ELECTRICALCHARACTERISTICS

Overoperatingtemperaturerange(TJ=-40°Cto+125°C),VIN=highestVOUT(nom)+1.0Vor2.7V(whicheverisgreater),IOUT=1mA,VEN1,2=1.2V,COUT=10µF,CNR=0.01µF,andadjustableLDOsaretestedatVOUT=3.0V,unlessotherwisenoted.TypicalvaluesareatTJ=25°C.

PARAMETER

VINVFB

Inputvoltagerange(1)

Internalreference(adjustableLDOs)Outputvoltagerange(adjustableLDOs)

VOUT

Accuracy(1)

∆VOUT%/∆VIN∆VOUT%/∆IOU

T

TESTCONDITIONSMIN2.71.200VFB

TYP1.225

MAX5.51.250

UNITVVV

5.5-VDO

+1.5

±10.050.8125

230800250+3

NominalOverVIN,IOUT,andT

TJ=25°C,IOUT=0mAVOUT+1.0V≤VIN≤5.5V,0µA≤IOUT≤250mAVOUT+1.0V≤VIN≤5.5V0µA≤IOUT≤250mA

-1.5-3

%%/V%/mAmVmA

Lineregulation(1)LoadregulationDropoutvoltage(2)

(VIN=VOUT(nom)-0.1V)Outputcurrentlimit

OneLDOenabledBothLDOsenabled2.8V,2.85VAdjustable

VDOICLIGNDISHDNIFBVnPSRRtSTRVIHVILIENTSDUVLO

IOUT1=IOUT2=250mAVOUT=0.9×VOUT(nom)

IOUT=1mA(enabledchannel)IOUT1=IOUT2=1mAto250mAVEN≤0.4V,0V≤VIN≤5.5VNoCNR,IOUT=250mACNR=0.01µF,IOUT=250mAf=100Hz,IOUT=250mAf=10kHz,IOUT=250mA

VOUT=2.85V,RL=30Ω,CNR=0.001µF

1.20

VIN=VEN=5.5VShutdownResetVINrisingVINfalling

TempincreasingTempdecreasing

2.25-1400

6001903000.30.1

GroundpincurrentShutdowncurrent(3)

µA

6002.01

µAµAµVrmsdBµs

VIN0.41

+160+140

2.65

100

VVµA°CVmV

FBpincurrent(adjustableLDOs)Outputnoisevoltage,BW=10Hz-100kHzPower-supplyrejectionratio(ripplerejection)Startuptime

Enablethresholdhigh(EN1,EN2)Enablethresholdlow(EN1,EN2)Enablepincurrent(EN1,EN2)ThermalshutdowntemperatureUndervoltagelockoutthresholdUndervoltagelockouthysteresis

80.0×VOUT11.8×VOUT

656560

(1)(2)(3)

MinimumVIN=VOUT+VDOor2.7V,whicheverisgreater.

VDOisnotmeasuredfor1.8VregulatorssinceminimumVIN=2.7V.

Fortheadjustableversion,thisappliesonlyafterVINisapplied;thenVENtransitionsfromhightolow.

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FUNCTIONALBLOCKDIAGRAM—

FIXEDVERSION

INCurrentLimit30µAOUT1INFUNCTIONALBLOCKDIAGRAM—

ADJUSTABLEVERSION

OUT1CurrentLimit90 kΩEN1

ThermalShutdownOUT2UVLOCurrentLimit30µAEN1

ThermalShutdownFB1OUT2UVLOCurrentLimit90 kΩFB2EN2

250kΩVREF1.225VQuickstart5pFTPS712xxFixed/FixedNRVREF1.225VQuickstart5pFTPS712xxAdj/AdjEN2

250kΩNRTable1.TERMINALFUNCTIONS

TERMINALNAMEINGNDOUT1OUT2EN1EN2FB1/NCFB2/NCNRNC

DRC15,Pad3410762

Ground

Outputoftheregulator.Asmall2.2µFceramiccapacitorisrequiredfromthispintogroundtoassurestability.

SameasOUT1butforLDO2.

Drivingtheenablepin(EN)highturnsonLDO1.DrivingthispinlowputsLDO1intoshutdownmode,reducingoperatingcurrent.TheenablepinshouldbeconnectedtoINifnotused.SameasEN1butcontrolsLDO2.

FeedbackforCH1adjustableversion;noconnectionfornon-adjustableCH1.FeedbackforCH2adjustableversion;noconnectionfornon-adjustableCH2.

Noisereductionpin;connectanexternalbypasscapacitortoreduceLDOoutputnoise.Noconnection.

DESCRIPTION

Unregulatedinputsupply.Asmall0.1µFcapacitorshouldbeconnectedfromINtoGND.

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TYPICALCHARACTERISTICS

ForallvoltageversionsatTJ=25°C,VIN=VOUT(nom)+1V,IOUT=1mA,VEN=1.2V,COUT=2.2µF,andCNR=0.01µF,

unlessotherwisenoted.

OUTPUTVOLTAGEvsINPUTVOLTAGE

1.00.80.60.4VOUT(%)0.20−0.2−0.4−0.6−0.8−1.0

3.0

3.5

4.0

4.5VIN(V)

5.0

5.5

6.0

−40_C+125_C+25_CVOUT(%)1.00.80.60.40.20−0.2−0.4−0.6−0.8−1.0

0

50

100

150

200

250

IOUT(mA)

+125_C+25_C−40_COUTPUTVOLTAGEvsOUTPUTCURRENT

Figure1.Figure2.

DROPOUTVOLTAGEvsINPUTVOLTAGE

(ADJUSTABLEVERSION)

200180

OUTPUTVOLTAGEvsTEMPERATURE

1.0

0.5160DropoutVoltage(mV)IOUT=10mA14012010080604020

TJ=−40_CTJ=+125_CTJ=+25_CVOUT(%)0

IOUT=125mA−0.5−1.0

−1.5

−40−25−10

IOUT=250mA0

5

20

35

50

65

80

95

110125

2.7

2.9

3.1

3.3

3.5

3.7

3.94.1

4.3

4..7

4.9

JunctionTemperature(_C)

VIN(V)

Figure3.

TPS71256

DROPOUTVOLTAGEvsOUTPUTCURRENT

200

TJ=+125_CDropoutVoltage(mV)DropoutVoltage(mV)150

200

Figure4.

TPS71256

DROPOUTVOLTAGEvsJUNCTIONTEMPERATURE

250

150

IOUT=250mA100

100

TJ=+25_C50

TJ=−40_C50

00

50

100

150

200

250

IOUT(mA)

0

−40−25−10

5203550658095110125

Junction Temperature (°C)

Figure5.Figure6.

5

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TYPICALCHARACTERISTICS(continued)

ForallvoltageversionsatTJ=25°C,VIN=VOUT(nom)+1V,IOUT=1mA,VEN=1.2V,COUT=2.2µF,andCNR=0.01µF,unlessotherwisenoted.

GROUNDPINCURRENTvsINPUTVOLTAGE

400375350IGND(µA)IGND(µA)325300275250225200

2.7

3.2

3.7

4.2VIN(V)

4.7

5.2

5.7

+25_C−40_C+125_C400375350325

+125_C300275250225200

0

50

100

150

200

250

IOUT(mA)

−40_C+25_CGROUNDPINCURRENTvsIOUT

Figure7.Figure8.

GROUNDPINCURRENTvsJUNCTIONTEMPERATURE

(DISABLED)

500

VEN1=VEN2=1.2VVIN=3.8V450400350IGND(nA)300250200150100500

VEN1=VEN2=0.4VVIN=3.8VGROUNDPINCURRENTvsJUNCTIONTEMPERATURE

400375350IGND(µA)325300275250225200

−40−25−10

5

20

35

50

65

80

95

110125

JunctionTemperature(_C)

−40−25−105203550658095110125

JunctionTemperature(_C)

Figure9.Figure10.

TPS71256

LINETRANSIENTRESPONSE

COUT1=COUT2=10µF3.8V

VIN

3.2V

CURRENTLIMITvsJUNCTIONTEMPERATURE

800750CurrentLimit(mA)700650600550500450

400

−40−25−10

10mV/div

VIN=3.8VIOUT=250mAIOUT=1mAVOUT1

10mV/divVOUT2

5203550658095110125

100µs/div

JunctionTemperature(_C)

Figure11.Figure12.

6

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TYPICALCHARACTERISTICS(continued)

ForallvoltageversionsatTJ=25°C,VIN=VOUT(nom)+1V,IOUT=1mA,VEN=1.2V,COUT=2.2µF,andCNR=0.01µF,unlessotherwisenoted.

TPS71256

LOADTRANSIENTRESPONSE

ANDVOUT2CROSSTALK

2mV/div

COUT2=10µFVOUT2

TPS71256

CHANNEL-TO-CHANNELISOLATIONvsFREQUENCY

6050ChannelIsolation(dB)403020100

COUT1=COUT2=10µFIOUT1=0mAto500mASinusoidalLoadIOUT2=25mA0.1

1

10Frequency(Hz)

100

1k

100mV/div

COUT1=10µFVOUT1

250mA10mA200mA/div

IOUT1

20µs/div

Figure13.

TPS71256

TURN-ON/OFFRESPONSEANDVOUT2CROSSTALK

CNR=0.01µF20mV/div

CNR=0.001µFIOUT1=IOUT2=250mACOUT1=COUT2=10µFVOUT2

Figure14.

TPS71229

POWER-UP/POWER-DOWN

IOUT1=IOUT2=250mAVIN1V/divVOUT1VOUT21V/div

VOUT1VEN1

50µs/div

50ms/div

Figure15.Figure16.

NOISESPECTRALDENSITY

COUT=2.2µF

SpectralNoiseDensity(nV/√Hz)VOUT=2.8V350300250200150100500100

IOUT=1mAIOUT=250mACNR=0.1µFVOUT=2.8VTOTALNOISEvsCNR

250

COUT=2.2µFIOUT=250mACOUT=2.2µFIOUT=0mA200TotalNoise(µVrms)COUT=10µFIOUT=250mA150

100

COUT=10µFIOUT=0mA50

0

110100

CNR(pF)

1k10k100k1k

Frequency(Hz)

10k100k

Figure17.Figure18.

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TYPICALCHARACTERISTICS(continued)

ForallvoltageversionsatTJ=25°C,VIN=VOUT(nom)+1V,IOUT=1mA,VEN=1.2V,COUT=2.2µF,andCNR=0.01µF,unlessotherwisenoted.

NOISESPECTRALDENSITY

COUT=10µF

350SpectralNoiseDensity(nV/√Hz)300250200150100500100

IOUT=1mAIOUT=250mASpectralNoiseDensity(nV/√Hz)CNR=0.01µFVOUT=2.8V180160140120100806040200100

1k

Frequency(Hz)

10k

100k

0.1µF0.047µF0.01µF0.001µFNOISESPECTRALDENSITYvsCNR

COUT=10µFIOUT=250mAVOUT=2.8V1k

Frequency(Hz)

10k100k

Figure19.

PSRR(RIPPLEREJECTION)vsFREQUENCY

807060PSRR(dB)PSRR(dB)50403020100

VOUT=2.8VCOUT=2.2µFCNR=0.01µF10

100

1k

10k

100k

1M

10M

IOUT=1mAIOUT=250mA8070605040302010010

Frequency(Hz)

VOUT=2.8VCOUT=10µFCNR=0.01µF100

1k

Figure20.

PSRR(RIPPLEREJECTION)vsFREQUENCY

IOUT=1mAIOUT=250mA10k100k1M10M

Frequency(Hz)

Figure21.

PSRR(RIPPLEREJECTION)vsVIN-VOUT

8070

f=1kHz60PSRR(dB)504030201000

0.2

0.4

0.6

0.8

1.0

1.2

1.4

VIN−VOUT(V)f=100kHzVOUT=2.8VIOUT=250mACOUT=10µFCNR=0.01µF1.6

1.8

2.0

f=10kHzFigure22.

Figure23.

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APPLICATIONINFORMATION

TheTPS712xxfamilyofduallow-dropout(LDO)regulatorshasbeenoptimizedforuseinnoise-sensitivebattery-operatedequipment.Thede-vicefeaturesextremelylowdropout,highPSRR,ultralowoutputnoise,andlowquiescentcurrent(190µAtypicalperchannel).Whenbothoutputsaredisabled,thesupplycurrentsarereducedtolessthan2µA.AtypicalapplicationcircuitisshowninFig-ure24.TPS712xx

VININOUT1VOUT1

2.2µFEN1EN2GNDOUT2NR0.01µFVOUT2

2.2µF1.8Vorlessischosen,theminimumrecommendedoutputcapacitoris4.7µF.Anyceramiccapacitorthatmeetstheminimumoutputcapacitorrequirementsissuitable.CapacitorswithhigherESRmaybeused,providedtheESRislessthan1Ω.

OUTPUTNOISE

TheinternalvoltagereferenceisakeysourceofnoiseinanLDOregulator.TheTPS712xxhasanNRpinthatisconnectedtothevoltagereferencethrougha250kΩinternalresistor.The250kΩinternalresistor,inconjunctionwithanexternalceramicbypasscapacitorconnectedtotheNRpin,createsalow-passfiltertoreducethevoltagereferencenoiseand,therefore,thenoiseattheregulatoroutput.Toachieveafaststartup,the250kΩinternalresistorisshortedfor400µsafterthedeviceisenabled.Becausetheprimarynoisesourceistheinternalvoltagereference,theoutputnoisewillbegreaterforhigheroutputvoltageversions.Forthecasewherenonoisereductioncapacitorisused,thetypicalnoise(µVrms)over10Hzto100kHzis80timestheoutputvoltage.Ifa0.01µFcapacitorisusedfromtheNRpintoground,thenoise(µVrms)dropsto11.8timestheoutputvoltage.Forexample,theTPS71256exhibitsonly33µVrmsofoutputvoltagenoiseusinga0.01µFceramicbypasscapacitoranda2.2µFceramicoutputcapacitor.

0.1µFFigure24.TypicalApplicationCircuit

(fixed-voltageversions)

INPUTANDOUTPUTCAPACITORREQUIREMENTS

A0.1µForlargerceramicinputbypasscapacitor,connectedbetweenINandGNDandlocatedclosetotheTPS712xx,isrequiredforstability.Itimprovestransientresponse,noiserejection,andripplerejec-tion.Ahigher-valueinputcapacitormaybenecessaryiflarge,fast-rise-timeloadtransientsareanticipatedandthedeviceislocatedseveralinchesfromthepowersource.

TheTPS712xxrequiresanoutputcapacitorconnec-tedbetweentheoutputsandGNDtostabilizetheinternalcontrolloops.Theminimumrecommendedoutputcapacitoris2.2µF.Ifanoutputvoltageof

STARTUPCHARACTERISITCS

Tominimizestartupovershoot,theTPS712xxwillinitiallytargetanoutputvoltagethatisapproximately80%ofthefinalvalue.Toavoidadelayedstartuptime,noisereductioncapacitorsof0.01µForlessarerecommended.Largernoisereductioncapacitorswillcausetheoutputtoholdat80%untilthevoltageonthenoisereductioncapacitorexceeds80%ofthebandgapvoltage.Thetypicalstartuptimewitha0.001µFnoisereductioncapacitoris60µs.Onceoneoftheoutputvoltagesispresent,thestartuptimeoftheotheroutputwillnotbeaffectedbythenoisereductioncapacitor.

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PROGRAMMINGTHETPS71202ADJUSTABLELDOREGULATOR

TheoutputvoltageoftheTPS71202dualadjustableregulatorisprogrammedusinganexternalresistordivider,asshowninFigure25.TheoutputvoltageiscalculatedusingEquation1:

VOUT+VREF 1)R1

R2

C1+

(3 105) (R1)R2)

(R1 R2)

(pF)

(3)

ǒǓ(1)

ThesuggestedvalueofthiscapacitorforseveralresistorratiosisshowninFigure25.Ifthiscapacitorisnotused(suchasinaunity-gainconfiguration)orifanoutputvoltage≤1.8Vischosen,thentheminimumrecommendedoutputcapacitoris4.7µFinsteadof2.2µF.

whereVREF=1.225V(theinternalreferencevolt-age).

ResistorsR2andR4shouldbechosenforapproxi-matelya40µAdividercurrent.Lowervalueresistorscanbeusedforimprovednoiseperformance,butwillconsumemorepower.HighervaluesshouldbeavoidedbecauseleakagecurrentatFBincreasestheoutputvoltageerror.Therecommendeddesignpro-cedureistochooseR2=30.1kΩtosetthedividercurrentat40µA,andthencalculateR1usingEquation2:

R1+

DROPOUTVOLTAGE

TheTPS712xxusesaPMOSpasstransistortoachieveextremelylowdropout.When(VIN-VOUT)islessthanthedropoutvoltage(VDO),thePMOSpassdeviceisinitslinearregionofoperationandtheinput-to-outputresistanceistheRDS,ONofthePMOSpasselement.DropoutvoltagesatlowercurrentscanbeapproximatedbycalculatingtheeffectiveRDS,ONofthepasselementandmultiplyingthatresistancebytheloadcurrent.RDS,ONofthepasselementcanbeobtainedbydividingthedropoutvoltagebytheratedoutputcurrent.FortheTPS71256,theRDS,ONofthepasselementis84mΩ.ThedropoutvoltageoftheTPS712xxwillbelessforhigheroutputvoltageversions.ThisisbecausethePMOSpasselementwillhaveloweron-resistanceduetoincreasedgatedrive.

ǒVV

OUTREF

*1 R2

Ǔ

(2)

Toimprovethestabilityandnoiseperformanceoftheadjustableversion,asmallcompensationcapacitorcanbeplacedbetweenOUTandFB.

Forvoltages≤1.8V,thevalueofthiscapacitorshouldbe100pF.Forvoltages>1.8V,theapproxi-matevalueofthiscapacitorcanbecalculatedasEquation3:

TPS71202

VININOUT1R1EN1EN20.1µFOUT2R3NR0.01µFGNDFB2R4C22.2µFFB1R2C12.2µFVOUT1

Output Voltage Programming Guide

VOUT1.225 V1.5 V

R1/R3Short7.15 kΩ31.6 kΩ43.2 kΩ49.9 kΩ86.6 kΩ

R2/R4Open30.1 kΩ30.1 kΩ30.1 kΩ30.1 kΩ30.1 kΩ

C1/C2Open100 pF22 pF15 pF15 pF15 pF

VOUT22.5 V3.0 V3.3 V4.75 V

Figure25.TPS71202AdjustableLDORegulatorProgramming

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SBVS049B–MAY2004–REVISEDMARCH2005

TRANSIENTRESPONSE

Aswithanyregulator,increasingthesizeoftheoutputcapacitorwillreduceover/undershootmagni-tudebutincreasedurationofthetransientresponse.Intheadjustableversion,theadditionofacapacitor,CFB,fromtheoutputtothefeedbackpinwillalsoimprovestabilityandtransientresponse.Thetransi-entresponseoftheTPS712xxisenhancedwithanactivepull-downthatengageswhentheoutputisover-voltaged.Theactivepull-downdecreasestheoutputrecoverytimewhentheloadisremoved.Figure13intheTypicalCharacteristicssectionshowstheoutputtransientresponse.

Dependingonpowerdissipation,thermalresistance,andambienttemperature,thethermalprotectioncircuitmaycycleonandoff.Thislimitsthedissipationoftheregulator,protectingitfromdamageduetooverheating.

Anytendencytoactivatethethermalprotectioncircuitindicatesexcessivepowerdissipationoraninad-equateheatsink.Forreliableoperation,junctiontem-peratureshouldbelimitedto+125°Cmaximum.Toestimatethemarginofsafetyinacompletedesign(includingheatsink),increasetheambienttempera-tureuntilthethermalprotectionistriggered;useworst-caseloadsandsignalconditions.Forgoodreliability,thermalprotectionshouldtriggeratleast+35°Cabovethemaximumexpectedambientcon-ditionofyourapplication.Thisproducesaworst-casejunctiontemperatureof+125°Catthehighestex-pectedambienttemperatureandworst-caseload.TheinternalprotectioncircuitryoftheTPS712xxwasdesignedtoprotectagainstoverloadconditions.Itwasnotintendedtoreplaceproperheatsinking.ContinuouslyrunningtheTPS712xxintothermalshutdownwilldegradedevicereliability.

SHUTDOWN

BothenablepinsareactivehighandarecompatiblewithstandardTTL-CMOSlevels.ThedeviceisonlycompletelydisabledwhenbothEN1andEN2arelogiclow.Inthisstate,theLDOiscompletelyoffandthegroundpincurrentdropstoapproximately100nA.Withoneoutputdisabled,thegroundpincurrentisslightlygreaterthanhalfthenominalvalue.Whenshutdowncapabilityisnotrequired,theenablepinsshouldbeconnectedtotheinputsupply.

POWERDISSIPATION

Theabilitytoremoveheatfromthedieisdifferentforeachpackagetype,presentingdifferentconsider-ationsinthePCBlayout.ThePCBareaaroundthedevicethatisfreeofothercomponentsmovestheheatfromthedevicetotheambientair.PerformancedataforaJEDEChigh-KboardisshownintheDissipationRatingstable.Usingheaviercopperwillincreasetheeffectivenessinremovingheatfromthedevice.Theadditionofplatedthrough-holestoheat-dissipatinglayerswillalsoimprovetheheat-sinkeffectiveness.

Powerdissipationdependsoninputvoltageandloadconditions.Powerdissipationisequaltotheproductoftheoutputcurrenttimesthevoltagedropacrosstheoutputpasselement(VINtoVOUT):PD+(VIN*VOUT) IOUT

(4)Powerdissipationcanbeminimizedbyusingthelowestpossibleinputvoltagenecessarytoassuretherequiredoutputvoltage.

INTERNALCURRENTLIMIT

TheTPS712xxinternalcurrentlimithelpsprotecttheregulatorduringfaultconditions.Duringcurrentlimit,theoutputwillsourceafixedamountofcurrentthatislargelyindependentoftheoutputvoltage.

TheTPS712xxPMOS-passtransistorshaveabuilt-inbackdiodethatconductsreversecurrentwhentheinputvoltagedropsbelowtheoutputvoltage(thatis,duringpower-down).Currentisconductedfromtheoutputtotheinputandisnotinternallylimited.Ifextendedreversevoltageoperationisanticipated,externallimitingmaybeappropriate.

THERMALPROTECTION

Thermalprotectiondisablesbothoutputswhenthejunctiontemperatureofeitherchannelrisestoap-proximately+160°C,allowingthedevicetocool.Whenthejunctiontemperaturecoolstoapproxi-mately+140°C,theoutputcircuitryisagainenabled.

11

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PACKAGINGINFORMATION

OrderableDeviceTPS71202DRCRTPS71202DRCRG4TPS71202DRCTTPS71219DRCRTPS71219DRCRG4TPS71219DRCTTPS71229DRCRTPS71229DRCRG4TPS71229DRCTTPS71229DRCTG4TPS71247DRCRTPS71247DRCRG4TPS71247DRCTTPS71256DRCRTPS71256DRCTTPS71257DRCRTPS71257DRCRG4TPS71257DRCT

(1)

Status(1)ACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEACTIVEPREVIEWPREVIEWACTIVEACTIVEACTIVE

PackageTypeSONSONSONSONSONSONSONSONSONSONSONSONSONSONSONSONSONSON

PackageDrawingDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRCDRC

PinsPackageEcoPlan(2)

Qty101010101010101010101010101010101010

3000Green(RoHS&

noSb/Br)3000Green(RoHS&

noSb/Br)250

Green(RoHS&noSb/Br)

Lead/BallFinishCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCUNIPDAUCallTICallTICUNIPDAUCUNIPDAUCUNIPDAU

MSLPeakTemp(3)Level-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEARCallTICallTI

Level-2-260C-1YEARLevel-2-260C-1YEARLevel-2-260C-1YEAR

3000Green(RoHS&

noSb/Br)3000Green(RoHS&

noSb/Br)250

Green(RoHS&noSb/Br)

3000Green(RoHS&

noSb/Br)3000Green(RoHS&

noSb/Br)250250

Green(RoHS&noSb/Br)Green(RoHS&noSb/Br)

3000Green(RoHS&

noSb/Br)3000Green(RoHS&

noSb/Br)2503000250

Green(RoHS&noSb/Br)

TBDTBD

3000Green(RoHS&

noSb/Br)3000Green(RoHS&

noSb/Br)250

Green(RoHS&noSb/Br)

Themarketingstatusvaluesaredefinedasfollows:ACTIVE:Productdevicerecommendedfornewdesigns.

LIFEBUY:TIhasannouncedthatthedevicewillbediscontinued,andalifetime-buyperiodisineffect.

NRND:Notrecommendedfornewdesigns.Deviceisinproductiontosupportexistingcustomers,butTIdoesnotrecommendusingthispartinanewdesign.

PREVIEW:Devicehasbeenannouncedbutisnotinproduction.Samplesmayormaynotbeavailable.OBSOLETE:TIhasdiscontinuedtheproductionofthedevice.

(2)

EcoPlan-Theplannedeco-friendlyclassification:Pb-Free(RoHS)orGreen(RoHS&noSb/Br)-pleasecheckhttp://www.ti.com/productcontentforthelatestavailabilityinformationandadditionalproductcontentdetails.TBD:ThePb-Free/Greenconversionplanhasnotbeendefined.

Pb-Free(RoHS):TI'sterms\"Lead-Free\"or\"Pb-Free\"meansemiconductorproductsthatarecompatiblewiththecurrentRoHSrequirementsforall6substances,includingtherequirementthatleadnotexceed0.1%byweightinhomogeneousmaterials.Wheredesignedtobesolderedathightemperatures,TIPb-Freeproductsaresuitableforuseinspecifiedlead-freeprocesses.

Green(RoHS&noSb/Br):TIdefines\"Green\"tomeanPb-Free(RoHScompatible),andfreeofBromine(Br)andAntimony(Sb)basedflameretardants(BrorSbdonotexceed0.1%byweightinhomogeneousmaterial)

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(3)

MSL,PeakTemp.--TheMoistureSensitivityLevelratingaccordingtotheJEDECindustrystandardclassifications,andpeaksoldertemperature.

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