LP2954AIMXNOPB,LP2954AIMNOPB,LP2954AISXNOPB, 规格书,Datasheet 资料

LP2954,LP2954A

LP2954/LP2954A 5V and Adjustable Micropower Low-Dropout Voltage Regulators

Literature Number: SNVS096C

LP2954/LP2954A

5V

and

Adjustable

Micropower

Low-Dropout

Voltage

Regulators

April2005

LP2954/LP2954A

5VandAdjustableMicropowerLow-DropoutVoltage

Regulators

GeneralDescriptionFeatures

TheLP2954isa5Vmicropowervoltageregulatorwithvery

lowquiescentcurrent(90µAtypicalat1mAload)andvery

lowdropoutvoltage(typically60mVatlightloadsand(LP2954IMandLP2954AIM)

470mVat250mAloadcurrent).

Thequiescentcurrentincreasonlyslightlyatdropout

(120µAtypical),whichprolongsbatterylife.

TheLP2954withafixed5Voutputisavailableinthethree-

leadTO-220andTO-263packages.TheadjustableLP2954

isprovidedinan8-leadsurfacemount,smalloutlinepack-

age.Theadjustableversionalsoprovidesaresistornetwork

whichcanbepinstrappedtottheoutputto5V.

Reverbatteryprotectionisprovided.

Thetightlineandloadregulation(0.04%typical),aswellas

verylowoutputtemperaturecoefficientmaketheLP2954

wellsuitedforuasalow-powervoltagereference.

Outputaccuracyisguaranteedatbothroomtemperature

andovertheentireoperatingtemperaturerange.

n5Voutputwithin1.2%overtemperature(Agrade)

nAdjustable1.23to29Voutputvoltageavailable

nGuaranteed250mAoutputcurrent

nExtremelylowquiescentcurrent

nLowdropoutvoltage

nReverbatteryprotection

nExtremelytightlineandloadregulation

nVerylowtemperaturecoefficient

nCurrentandthermallimiting

nPincompatiblewithLM2940andLM340(5Vversion

only)

nAdjustableversionaddserrorflagtowarnofoutputdrop

andalogic-controlledshutdown

Applications

nHigh-efficiencylinearregulator

nLowdropoutbattery-poweredregulator

PackageOutlineandOrdering

Information

TO-2203–LeadPlasticPackage

TO-2633-LeadPlasticSurface-MountPackage

01112809

TopView

01112802

FrontView

OrderNumberLP2954AITorLP2954IT

SeeNSPackageT03B

SO-8SmallOutlineSurfaceMount

01112810

SideView

OrderNumberLP2954AISorLP2954IS

SeeNSPackageTS3B

01112833

TopView

OrderNumberLP2954AIMorLP2954IM

SeeNSPackageM08A

©2005NationalSemiconductorCorporationDS011128

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OrderingInformation

OrderNumberTemp.RangePackageNSPackage

LP2954AIT−40to+125TO-220TO3B

LP2954IT

LP2954AIS−40to+125TO-263TS3B

LP2954IS

LP2954AIM−40to+125SO-8M08A

LP2954IM

(T)˚C(JEDEC)Number

J

2

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LP2954/LP2954A

5V

AbsoluteMaximumRatings

(Note1)

IfMilitary/Aerospacespecifieddevicesarerequired,

pleacontacttheNationalSemiconductorSalesOffice/

Distributorsforavailabilityandspecifications.

OperatingJunctionTemperature

Range

LP2954AI/LP2954I−40˚Cto+125˚C

StorageTemperatureRange−65˚Cto+150˚C

LeadTemperature

(Soldering,5conds)260˚C

PowerDissipation(Note2)InternallyLimited

InputSupplyVoltage−20Vto+30V

ESDRating2kV

ElectricalCharacteristics

LimitsinstandardtypefaceareforT=25˚C,boldtypefaceappliesoverthe−40˚Cto+125˚Ctemperaturerange.Limits

J

areguaranteedbyproductiontestingorcorrelationtechniquesusingstandardStatisticalQualityControl(SQC)methods.Un-

lessotherwinoted:V

INLL

=6V,I=1mA,C=2.2µF.

SymbolParameterConditionsTypical2954AI2954IUnits

VOutputVoltage5.04.9755.0254.9505.050V

O

1mA≤I

L

≤250mA5.04.9305.0704.8805.120

OutputVoltage(Note3)

Temp.Coefficient

LineRegulationV=6Vto30V0.030.100.20

IN

0.200.40

LoadRegulationI=1to250mA

L

I=0.1to1mA0.04%

L

(Note4)

V

INOL

–VDropoutVoltageI=1mA60100100mV

(Note5)150150

I

L

=50mA240300300

I=100mA310400400

L

I

L

=250mA470600600

I

GNDL

GroundPinCurrentI=1mA90150150µA

(Note6)180180

I=50mA1.122mA

L

I

L

=100mA4.566

I

L

=250mA212828

IGroundPinV=4.5V170170

GNDIN

CurrentatDropout120210210µA

(Note6)

I

LIMITOUT

CurrentLimitV=0V380500500mA

ThermalRegulation(Note7)

0.050.20.2%/W

530530

420420

520520

800800

2.52.5

88

3333

0.160.20

0.200.30

%

MinMaxMinMax

20100150ppm/˚C

4.9405.0604.9005.100

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ElectricalCharacteristics

(Continued)

LimitsinstandardtypefaceareforT=25˚C,boldtypefaceappliesoverthe−40˚Cto+125˚Ctemperaturerange.Limits

J

areguaranteedbyproductiontestingorcorrelationtechniquesusingstandardStatisticalQualityControl(SQC)methods.Un-

lessotherwinoted:V

INLL

=6V,I=1mA,C=2.2µF.

ParameterConditionsTypical2954AI2954IUnitsSymbol

OutputNoiC=2.2µF400µVRMSe

Voltage

(10Hzto100kHz)C=33µF260

I

L

=100mA

L

C=33µF(Note9)80

L

(Note10)1.2301.2151.2451.2051.255VReferenceVoltage

V=2.5Vto0.030.10.2%/ReferenceVoltage

INREF

VO(NOM)+1VVLineRegulation

V=2.5Vto

IN

VO(NOM)+1Vto30V

(Note11)

1.2051.2551.1901.270

0.20.4%

Ln

MinMaxMinMax

AdditionalSpecificationsfortheAdjustableDevice(LP2954AIMandLP2954IM)

V

REF

∆V

REF

∆V

REF

/∆TReferenceVoltage

Temperature

Coefficient

I

B

(FB)FeedbackPinBias204040nA

IGroundPinCurrentatV

GNDSHUTDOWN

I(SINK)3030mAOutput"OFF"(Note12)

O

Current6060

(Note3)20ppm/˚C

105140140µA≤1.1V

2020PulldownCurrent

0.011Output"HIGH"IV=30V1µA

150250V250mVOutput"LOW"VoltageV=V(NOM)−0.5V

−60−80−35−80−35mV(Note13)V(MAX)UpperThreshold

−85−110−55−110−55mV(Note13)V(MIN)LowerThreshold

15mV(Note13)HYSTHysteresis

−95−25−95−25Voltage

−160−40−160−40Voltage

2LeakageCurrent2

400400(COMP)=400µA

Shutdown(Note6)

DropoutDetectionComparator

OHOH

OLINO

−7.57.5−7.57.5mV(ReferredtoV)VInputOfftVoltage3

−1010−1010

−3030−3030nAIInputBiasCurrentV(S/D)=0Vto5V10

−5050−5050

mVHYSTHysteresis6

I

O

REFOS

THR

THR

BIN

ShutdownInput

±

4

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LP2954/LP2954A

5V

ElectricalCharacteristics

(Continued)

Note1:Absolutemaximumratingsindicatelimitsbeyondwhichdamagetothecomponentmayoccur.Electricalspecificationsdonotapplywhenoperatingthe

deviceoutsideofitsratedoperatingconditions.

Note2:Themaximumallowablepowerdissipationisafunctionofthemaximumjunctiontemperature,T(MAX),thejunction-to-ambientthermalresistance,θ,

JJ-A

andtheambienttemperature,T.Themaximumallowablepowerdissipationatanyambienttemperatureiscalculatedusing:

A

.

Exceedingthemaximumallowablepowerdissipationwillresultinexcessivedietemperature,andtheregulatorwillgointothermalshutdown.Thejunction-to-

ambientthermalresistanceoftheTO-220(withoutheatsink)is60˚C/W,73˚C/WfortheTO-263,and160˚C/WfortheSO-8.IftheTO-263packageisud,the

thermalresistancecanbereducedbyincreasingtheP.C.boardcopperareathermallyconnectedtothepackage:Using0.5squareinchesofcopperarea,θ

JA

is

50˚C/W;with1squareinchofcopperarea,θis37˚C/W;andwith1.6ormoresquareinchesofcopperarea,θis32˚C/W.Thejunction-to-cathermalresistance

JAJA

is3˚C/W.Ifanexternalheatsinkisud,theeffectivejunction-to-ambientthermalresistanceisthesumofthejunction-to-caresistance(3˚C/W),thespecified

thermalresistanceoftheheatsinklected,andthethermalresistanceoftheinterfacebetweentheheatsinkandtheLP2954.Sometypicalvaluesarelistedfor

interfacematerialsudwithTO-220:

TABLE1.TypicalValuesofCa-to-Heatsink

ThermalResistance(˚C/W)(DatafromAAVIDEng.)

Siliconegrea1.0ThermasilIII1.3

Dryinterface1.3ThermasilII1.5

Micawithgrea1.4Thermalfilm(0.002)withgrea2.2

TABLE2.TypicalValuesofCa-to-Heatsink

ThermalResistance(˚C/W)(DatafromThermalloy)

Note3:Outputvoltagetemperaturecoefficientisdefinedastheworstcavoltagechangedividedbythetotaltemperaturerange.

Note4:Regulationismeasuredatconstantjunctiontemperatureusinglowdutycyclepultesting.Partsaretestedparatelyforloadregulationintheload

ranges0.1mA–1mAand1mA–250mA.Changesinoutputvoltageduetoheatingeffectsarecoveredbythethermalregulationspecification.

Note5:Dropoutvoltageisdefinedastheinputtooutputdifferentialatwhichtheoutputvoltagedrops100mVbelowthevaluemeasuredwitha1Vdifferential.

Note6:Groundpincurrentistheregulatorquiescentcurrent.Thetotalcurrentdrawnfromthesourceisthesumoftheloadcurrentplusthegroundpincurrent.

Note7:ThermalregulationisdefinedasthechangeinoutputvoltageatatimeTafterachangeinpowerdissipationisapplied,excludingloadorlineregulation

effects.Specificationsarefor200mAloadpulatV=20V(3Wpul)forT=10ms.

IN

Note8:Whenudindual-supplysystemswheretheregulatorloadisreturnedtoanegativesupply,theoutputvoltagemustbediode-clampedtoground.

Note9:Connecta0.1µFcapacitorfromtheoutputtothefeedbackpin.

Note10:V

REFOUTININL

≤V≤(V≤30V,100µA≤I≤250mA.

−1V),2.3V≤V

Note11:Twoperatetestsareperformed,onecoveringV=2.5VtoV(NOM)+1VandtheothertestforV=2.5VtoV(NOM)+1Vto30V.

INOINO

Note12:V(NOM).

SHUTDOWNO

≤1.1V,VOUT=V

Note13:ComparatorthresholdsareexpresdintermsofavoltagedifferentialattheFeedbackterminalbelowthenominalreferencevoltagemeasuredat

V=V(NOM)+1V.Toexpressthethresholdsintermsofoutputvoltagechange,multiplybytheErroramplifiergain,whichisV/V=(R1+R2)/R2.

INOOUTREF

Note14:Humanbodymodel,200pFdischargedthrough1.5kΩ.

TypicalPerformanceCharacteristics

QuiescentCurrentQuiescentCurrent

0111281201112813

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TypicalPerformanceCharacteristics

GroundPinCurrentvsLoadGroundPinCurrent

(Continued)

01112814

01112815

GroundPinCurrentOutputNoiVoltage

01112816

01112817

RippleRejectionRippleRejection

01112818

01112819

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LP2954/LP2954A

5V

TypicalPerformanceCharacteristics

RippleRejectionLineTransientRespon

(Continued)

01112820

01112821

LineTransientResponOutputImpedance

01112822

01112823

LoadTransientResponLoadTransientRespon

0111282401112825

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TypicalPerformanceCharacteristics

DropoutCharacteristicsThermalRespon

(Continued)

01112826

01112827

Short-CircuitOutput

CurrentandMaximumMaximumPowerDissipation

OutputCurrent(TO-263)(See(Note2))

01112828

01112811

ApplicationHints

EXTERNALCAPACITORS

A2.2µF(orgreater)capacitorisrequiredbetweenthe

outputpinandthegroundtoassurestability(refertoFigure

1).Withoutthiscapacitor,thepartmayoscillate.Mosttypes

oftantalumoraluminumelectrolyticswillworkhere.Film

typeswillwork,butaremoreexpensive.Manyaluminum

electrolyticscontainelectrolyteswhichfreezeat−30˚C,

whichrequirestheuofsolidtantalumsbelow−25˚C.The

importantparametersofthecapacitorareanESRofabout

5Ωorlessandaresonantfrequencyabove500kHz(the

ESRmayincreabyafactorof20or30asthetemperature

isreducedfrom25˚Cto−30˚C).Thevalueofthiscapacitor

maybeincreadwithoutlimit.Atlowervaluesofoutput

current,lessoutputcapacitanceisrequiredforstability.The

capacitorcanbereducedto0.68µFforcurrentsbelow

10mAor0.22µFforcurrentsbelow1mA.

A1µFcapacitorshouldbeplacedfromtheinputpinto

groundifthereismorethan10inchesofwirebetweenthe

inputandtheACfiltercapacitororifabatteryinputisud.

Programmingtheoutputforvoltagesbelow5Vrunstheerror

amplifieratlowergainsrequiringmoreoutputcapacitance

8

forstability.At3.3Voutput,aminimumof4.7µFisrequired.

Fortheworstcaconditionof1.23Voutputand250mAof

loadcurrent,a6.8µF(orlarger)capacitorshouldbeud.

StraycapacitancetotheFeedbackterminalcancauinsta-

bility.Thisproblemismostlikelytoappearwhenusinghigh

valueexternalresistorstottheoutputvoltage.Addinga

100pFcapacitorbetweentheOutputandFeedbackpins

andincreasingtheoutputcapacitanceto6.8µF(orgreater)

willcuretheproblem.

MINIMUMLOAD

Whenttingtheoutputvoltageusinganexternalresistive

divider,aminimumcurrentof1µAisrecommendedthrough

theresistorstoprovideaminimumload.

Itshouldbenotedthataminimumloadcurrentisspecifiedin

veraloftheelectricalcharacteristictestconditions,sothis

valuemustbeudtoobtaincorrelationonthetested

limits.Thepartisparametricallytesteddownto100µA,but

isfunctionalwithnoload.

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LP2954/LP2954A

5V

ApplicationHints

DROPOUTVOLTAGE

(Continued)

Thedropoutvoltageoftheregulatorisdefinedasthemini-

muminput-to-outputvoltagedifferentialrequiredfortheout-

putvoltagetostaywithin100mVoftheoutputvoltage

measuredwitha1Vdifferential.Thedropoutvoltagesfor

variousvaluesofloadcurrentarelistedunderElectrical

Characteristics.

IftheregulatorispoweredfromarectifiedACsourcewitha

capacitivefilter,theminimumAClinevoltageandmaximum

loadcurrentmustbeudtocalculatetheminimumvoltage

attheinputoftheregulator.Theminimuminputvoltage,

includingACrippleonthefiltercapacitor,mustnotdrop

belowthevoltagerequiredtokeeptheLP2954inregulation.

Itisalsoadvisabletoverifyoperatingatminimumoperating

ambienttemperature,sincetheincreasingESRofthefilter

capacitormakesthisaworst-catestfordropoutvoltage

duetoincreadrippleamplitude.

HEATSINKREQUIREMENTS

AheatsinkmayberequiredwiththeLP2954dependingon

themaximumpowerdissipationandmaximumambienttem-

peratureoftheapplication.Underallpossibleoperating

conditions,thejunctiontemperaturemustbewithinthe

rangespecifiedunderAbsoluteMaximumRatings.

Todetermineifaheatsinkisrequired,themaximumpower

dissipatedbytheregulator,P(max),mustbecalculated.Itis

importanttorememberthatiftheregulatorispoweredfrom

atransformerconnectedtotheACline,themaximum

specifiedACinputvoltagemustbeud(sincethispro-

ducesthemaximumDCinputvoltagetotheregulator).

Figure1showsthevoltagesandcurrentswhichareprent

inthecircuit.Theformulaforcalculatingthepowerdissi-

patedintheregulatorisalsoshowninFigure1.

latedvalueisbelow60˚C/W,anexternalheatsinkisre-

quired.Therequiredthermalresistanceforthisheatsinkcan

becalculatedusingtheformula:

θ

(H-A)(J-A)(J-C)(C-H)

=θ−θ−θ

where:

θ

(J-C)

isthejunction-to-cathermalresistance,whichis

specifiedas3˚C/WmaximumfortheLP2954.

θ

(C-H)

istheca-to-heatsinkthermalresistance,whichis

dependentontheinterfacingmaterial(ifud).Fordetails

andtypicalvalues,referto(Note2)listedattheendofthe

ELECTRICALCHARACTERISTICSction.

θ

(H-A)

istheheatsink-to-ambientthermalresistance.Itisthis

specification(listedontheheatsinkmanufacturersdata

sheet)whichdefinestheeffectivenessoftheheatsink.The

heatsinklectedmusthaveathermalresistancewhichis

equaltoorlowerthanthevalueofθ

(H-A)

calculatedfromthe

abovelistedformula.

PROGRAMMINGTHEOUTPUTVOLTAGE

Theregulatormaybepin-strappedfor5Voperationusingits

internalresistivedividerbytyingtheOutputandSenpins

togetherandalsotyingtheFeedbackand5VTappins

together.

Alternatively,itmaybeprogrammedforanyvoltagebetween

the1.23Vreferenceandthe30Vmaximumratingusingan

externalpairofresistors(eFigure2).Thecompleteequa-

tionfortheoutputvoltageis:

whereVisthe1.23VreferenceandIistheFeedback

REFFB

pinbiascurrent(−20nAtypical).Theminimumrecom-

mendedloadcurrentof1µAtsanupperlimitof1.2MΩon

thevalueofR2incaswheretheregulatormustworkwith

noload(eMINIMUMLOAD).I

FB

willproduceatypical2%

errorinVwhichcanbeeliminatedatroomtemperature

OUT

bytrimmingR1.Forbetteraccuracy,choosingR2=100kΩ

willreducethiserrorto0.17%whileincreasingtheresistor

programcurrentto12µA.Sincethetypicalquiescentcurrent

is120µA,thisaddedcurrentisnegligible.

01112805

*SeeExternalCapacitors

P=(V−5)I+(V)I

TotalINLING

FIGURE1.Basic5VRegulatorCircuit

Thenextparameterwhichmustbecalculatedisthemaxi-

mumallowabletemperatureri,T

R

(max).Thisiscalculated

byusingtheformula:

T

RJA

(max)=T(max)−T(max)

where:T(max)isthemaximumallowablejunction

J

temperature

T

A

(max)isthemaximumambienttemperature

UsingthecalculatedvaluesforT(max)andP(max),the

R

requiredvalueforjunction-to-ambientthermalresistance,

θ

(J-A)

,cannowbefound:

θ

(J-A)R

=T(max)/P(max)

Ifthecalculatedvalueis60˚C/Worhigher,theregulator

maybeoperatedwithoutanexternalheatsink.Ifthecalcu-

9

01112836

*SeeApplicationHints

**DrivewithTTL-lowtoshutdown

FIGURE2.AdjustableRegulator

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ApplicationHints

(Continued)

OUTPUTISOLATION

Theregulatoroutputcanbeleftconnectedtoanactive

voltagesource(suchasabattery)withtheregulatorinput

powerturnedoff,aslongastheregulatorgroundpinis

connectedtoground.Ifthegroundpinisleftfloating,

damagetotheregulatorcanoccuriftheoutputispulled

upbyanexternalvoltagesource.

REDUCINGOUTPUTNOISE

Inreferenceapplicationsitmaybeadvantageoustoreduce

theACnoiprentontheoutput.Onemethodistoreduce

regulatorbandwidthbyincreasingoutputcapacitance.This

isrelativelyinefficient,sincelargeincreasincapacitance

arerequiredtogetsignificantimprovement.

Noicanbereducedmoreeffectivelybyabypasscapacitor

placedacrossR1(refertoFigure2).Theformulaforlect-

ingthecapacitortobeudis:

DROPOUTDETECTIONCOMPARATOR

Thiscomparatorproducesalogic“LOW”whenevertheout-

putfallsoutofregulationbymorethanabout5%.Thisfigure

resultsfromthecomparator’sbuilt-inofftof60mVdivided

bythe1.23Vreference(refertoblockdiagramsonpage1).

The5%lowtriplevelremainsconstantregardlessofthe

programmedoutputvoltage.Anout-of-regulationcondition

canresultfromlowinputvoltage,currentlimiting,orthermal

limiting.

Figure3givesatimingdiagramshowingtherelationship

betweentheoutputvoltage,theERRORoutput,andinput

voltageastheinputvoltageisrampedupanddowntoa

regulatorprogrammedfor5Voutput.TheERRORsignal

becomeslowatabout1.3Vinput.Itgoeshighatabout5V

input,wheretheoutputequals4.75V.Sincethedropout

voltageisloaddependent,theinputvoltagetrippointswill

varywithloadcurrent.Theoutputvoltagetrippointdoesnot

vary.

Thecomparatorhasanopen-collectoroutputwhichrequires

anexternalpull-upresistor.Thisresistormaybeconnected

totheregulatoroutputorsomeothersupplyvoltage.Using

theregulatoroutputpreventsaninvalid“HIGH”onthecom-

paratoroutputwhichoccursifitispulleduptoanexternal

voltagewhiletheregulatorinputvoltageisreducedbelow

1.3V.Inlectingavalueforthepull-upresistor,notethat

whiletheoutputcansink400µA,thiscurrentaddstobattery

drain.Suggestedvaluesrangefrom100kΩto1MΩ.This

resistorisnotrequirediftheoutputisunud.

WhenV

IN

≤1.3V,theerrorflagpinbecomesahighimped-

ance,allowingtheerrorflagvoltagetoritoitspull-up

voltage.UsingV

OUT

asthepull-upvoltage(ratherthanan

external5Vsource)willkeeptheerrorflagvoltagebelow

1.2V(typical)inthiscondition.Theurmaywishtodivide

downtheerrorflagvoltageusingequal-valueresistors

(10kΩsuggested)toensurealow-levellogicsignalduring

anyfaultcondition,whilestillallowingavalidhighlogiclevel

duringnormaloperation.

Thisgivesavalueofabout0.1µF.Whenthisisud,the

outputcapacitormustbe6.8µF(orgreater)tomaintain

stability.The0.1µFcapacitorreducesthehighfrequency

gainofthecircuittounity,loweringtheoutputnoifrom260

µVto80µVusinga10Hzto100kHzbandwidth.Also,noi

isnolongerproportionaltotheoutputvoltage,soimprove-

mentsaremorepronouncedathighoutputvoltages.

SHUTDOWNINPUT

Alogic-levelsignalwillshutofftheregulatoroutputwhena

“LOW”(

<

1.2V)isappliedtotheShutdowninput.

Topreventpossiblemis-operation,theShutdowninputmust

beactivelyterminated.Iftheinputisdrivenfromopen-

collectorlogic,apull-upresistor(20kΩto100kΩrecom-

mended)shouldbeconnectedfromtheShutdowninputto

theregulatorinput.

IftheShutdowninputisdrivenfromasourcethatactively

pullshighandlow(likeanop-amp),thepull-upresistorisnot

required,butmaybeud.

Iftheshutdownfunctionisnottobeud,thecostofthe

pull-upresistorcanbesavedbysimplytyingtheShutdown

inputdirectlytotheregulatorinput.

IMPORTANT:SincetheAbsoluteMaximumRatingsstate

thattheShutdowninputcannotgomorethan0.3Vbelow

ground,therever-batteryprotectionfeaturewhichprotects

theregulatorinputissacrificediftheShutdowninputistied

directlytotheregulatorinput.

Ifrever-batteryprotectionisrequiredinanapplication,the

pull-upresistorbetweentheShutdowninputandtheregula-

torinputmustbeud.

01112837

*Inshutdownmode,ERRORwillgohighifithasbeenpulleduptoan

externalsupply.Toavoidthisinvalidrespon,pulluptoregulatoroutput.

**Exactvaluedependsondropoutvoltage.(SeeApplicationHints)

FIGURE3.ERROROutputTiming

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LP2954/LP2954A

5V

TypicalApplications

TypicalApplicationCircuit

01112801

5VRegulator

01112806

5VCurrentLimiter

01112807

*Outputvoltageequals+Vminusdropoutvoltage,whichvarieswithoutputcurrent.Currentlimitsat380mA(typical).

IN

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LP2954/LP2954A

5V

PhysicalDimensions

unlessotherwinoted

inches(millimeters)

TO-2203-LeadPlasticPackage

OrderNumberLP2954AITorLP2954IT

NSPackageT03B

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PhysicalDimensions

inches(millimeters)unlessotherwinoted(Continued)

TO-2633-LeadPlasticSurfaceMountPackage

OrderNumberLP2954AISorLP2954IS

NSPackageTS3B

SO-8SurfaceMountPackage

OrderNumberLP2954AIMorLP2954IM

NSPackageNumberM08A

14

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LP2954/LP2954A

5V

and

Adjustable

Micropower

Low-Dropout

Voltage

Regulators

Notes

Nationaldoesnotassumeanyresponsibilityforuofanycircuitrydescribed,nocircuitpatentlicensareimpliedandNationalrerves

therightatanytimewithoutnoticetochangesaidcircuitryandspecifications.

Forthemostcurrentproductinformationvisitusat.

LIFESUPPORTPOLICY

NATIONAL’SPRODUCTSARENOTAUTHORIZEDFORUSEASCRITICALCOMPONENTSINLIFESUPPORTDEVICESORSYSTEMS

WITHOUTTHEEXPRESSWRITTENAPPROVALOFTHEPRESIDENTANDGENERALCOUNSELOFNATIONALSEMICONDUCTOR

CORPORATION.Asudherein:

1.Lifesupportdevicesorsystemsaredevicesorsystems

which,(a)areintendedforsurgicalimplantintothebody,or

(b)supportorsustainlife,andwhofailuretoperformwhen

properlyudinaccordancewithinstructionsforu

providedinthelabeling,canbereasonablyexpectedtoresult

inasignificantinjurytotheur.

BANNEDSUBSTANCECOMPLIANCE

NationalSemiconductormanufacturesproductsanduspackingmaterialsthatmeettheprovisionsoftheCustomerProducts

StewardshipSpecification(CSP-9-111C2)andtheBannedSubstancesandMaterialsofInterestSpecification(CSP-9-111S2)andcontain

no‘‘BannedSubstances’’asdefinedinCSP-9-111S2.

NationalSemiconductor

AmericasCustomer

SupportCenter

Email:ck@Email:t@

Tel:1-800-272-9959

NationalSemiconductor

EuropeCustomerSupportCenter

Fax:+49(0)180-5308586

DeutschTel:+49(0)6995086208

EnglishTel:+44(0)8702402171

FrançaisTel:+33(0)141918790

NationalSemiconductor

AsiaPacificCustomer

SupportCenter

Email:t@

NationalSemiconductor

JapanCustomerSupportCenter

Fax:81-3-5639-7507

Email:ck@

Tel:81-3-5639-7560

2.Acriticalcomponentisanycomponentofalifesupport

deviceorsystemwhofailuretoperformcanbereasonably

expectedtocauthefailureofthelifesupportdeviceor

system,ortoaffectitssafetyoreffectiveness.

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IMPORTANTNOTICE

TexasInstrumentsIncorporatedanditssubsidiaries(TI)rervetherighttomakecorrections,modifications,enhancements,improvements,

andotherchangestoitsproductsandrvicesatanytimeandtodiscontinueanyproductorrvicewithoutnotice.Customersshould

obtainthelatestrelevantinformationbeforeplacingordersandshouldverifythatsuchinformationiscurrentandcomplete.Allproductsare

soldsubjecttoTI’stermsandconditionsofsalesuppliedatthetimeoforderacknowledgment.

TIwarrantsperformanceofitshardwareproductstothespecificationsapplicableatthetimeofsaleinaccordancewithTI’sstandard

warranty.TestingandotherqualitycontroltechniquesareudtotheextentTIdeemsnecessarytosupportthiswarranty.Exceptwhere

mandatedbygovernmentrequirements,testingofallparametersofeachproductisnotnecessarilyperformed.

TIassumesnoliabilityforapplicationsassistanceorcustomerproductdesign.Customersareresponsiblefortheirproductsand

applicationsusingTIcomponents.Tominimizetherisksassociatedwithcustomerproductsandapplications,customersshouldprovide

adequatedesignandoperatingsafeguards.

TIdoesnotwarrantorreprentthatanylicen,eitherexpressorimplied,isgrantedunderanyTIpatentright,copyright,maskworkright,

orotherTIintellectualpropertyrightrelatingtoanycombination,machine,orprocessinwhichTIproductsorrvicesareud.Information

publishedbyTIregardingthird-partyproductsorrvicesdoesnotconstitutealicenfromTItousuchproductsorrvicesora

warrantyorendormentthereof.Uofsuchinformationmayrequirealicenfromathirdpartyunderthepatentsorotherintellectual

propertyofthethirdparty,oralicenfromTIunderthepatentsorotherintellectualpropertyofTI.

ReproductionofTIinformationinTIdatabooksordatasheetsispermissibleonlyifreproductioniswithoutalterationandisaccompanied

byallassociatedwarranties,conditions,limitations,andnotices.Reproductionofthisinformationwithalterationisanunfairanddeceptive

businesspractice.TIisnotresponsibleorliableforsuchaltereddocumentation.Informationofthirdpartiesmaybesubjecttoadditional

restrictions.

ResaleofTIproductsorrviceswithstatementsdifferentfromorbeyondtheparametersstatedbyTIforthatproductorrvicevoidsall

expressandanyimpliedwarrantiesfortheassociatedTIproductorrviceandisanunfairanddeceptivebusinesspractice.TIisnot

responsibleorliableforanysuchstatements.

TIproductsarenotauthorizedforuinsafety-criticalapplications(suchaslifesupport)whereafailureoftheTIproductwouldreasonably

beexpectedtocauverepersonalinjuryordeath,unlessofficersofthepartieshaveexecutedanagreementspecificallygoverning

suchu.Buyersreprentthattheyhaveallnecessaryexpertiinthesafetyandregulatoryramificationsoftheirapplications,and

acknowledgeandagreethattheyaresolelyresponsibleforalllegal,regulatoryandsafety-relatedrequirementsconcerningtheirproducts

andanyuofTIproductsinsuchsafety-criticalapplications,notwithstandinganyapplications-relatedinformationorsupportthatmaybe

providedbyTI.Further,BuyersmustfullyindemnifyTIanditsreprentativesagainstanydamagesarisingoutoftheuofTIproductsin

suchsafety-criticalapplications.

TIproductsareneitherdesignednorintendedforuinmilitary/aerospaceapplicationsorenvironmentsunlesstheTIproductsare

specificallydesignatedbyTIasmilitary-gradeor"enhancedplastic."OnlyproductsdesignatedbyTIasmilitary-grademeetmilitary

specifications.BuyersacknowledgeandagreethatanysuchuofTIproductswhichTIhasnotdesignatedasmilitary-gradeissolelyat

theBuyer'srisk,andthattheyaresolelyresponsibleforcompliancewithalllegalandregulatoryrequirementsinconnectionwithsuchu.

TIproductsareneitherdesignednorintendedforuinautomotiveapplicationsorenvironmentsunlessthespecificTIproductsare

designatedbyTIascompliantwithISO/TS16949requirements.Buyersacknowledgeandagreethat,iftheyuanynon-designated

productsinautomotiveapplications,TIwillnotberesponsibleforanyfailuretomeetsuchrequirements.

FollowingareURLswhereyoucanobtaininformationonotherTexasInstrumentsproductsandapplicationsolutions:

ProductsApplications

Audio/audioCommunicationsandTelecom/communications

AmplifiersComputersandPeripherals/computers

DataConvertersConsumerElectronics/consumer-apps

DLP®ProductsEnergyandLighting/energy

DSPIndustrial/industrial

ClocksandTimers/clocksMedical/medical

InterfaceSecurity/curity

LogicSpace,AvionicsandDefen/space-avionics-defen

PowerMgmtTransportationandAutomotive/automotive

MicrocontrollersVideoandImaging/video

RFID

OMAPMobileProcessors/omap

WirelessConnectivity/wirelessconnectivity

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