Texas Instruments LM3253 Handleiding

Bekijk gratis de handleiding van Texas Instruments LM3253 (25 pagina’s), behorend tot de categorie Niet gecategoriseerd. Deze gids werd als nuttig beoordeeld door 11 mensen en kreeg gemiddeld 4.8 sterren uit 9 reviews. Heb je een vraag over Texas Instruments LM3253 of wil je andere gebruikers van dit product iets vragen? Stel een vraag

LM3253

www.ti.com

SNVS791Q–FEBRUARY2012–REVISEDMAY2013

LM3253High-CurrentStep-DownConverterfor2G/3G/4GRFPowerAmplifiers

CheckforSamples:LM3253

1

FEATURES

2

•High-EfficiencyPFMandPWMModeswith

DESCRIPTION

InternalSynchronousRectification

TheLM3253isaDC-DCconverteroptimizedfor

poweringmulti-mode2G/3G/4GRFpoweramplifiers

•AnalogBypassFunctionwithLowDropout

(PAs)fromasingleLithium-Ioncell.TheLM3253

Resistance(45mΩtyp.)

stepsdownaninputvoltagefrom2.7Vto5.5Vtoa

•DynamicallyAdjustableOutputVoltage,0.4V

dynamicallyadjustableoutputvoltageof0.4Vto3.6V.

to3.6V(typ.),inPFMandPWMmodes

TheoutputvoltageissetthroughaVCONanalog

•3AMaximumLoadCurrentinPWMMode

inputthatadjuststheoutputvoltagetoensure

efficientoperationatallpowerlevelsoftheRFPA.

•2.7MHz(average)PWMSwitchingFrequency

TheLM3253isoptimizedforUSBdatacard

•ModulatedSwitchingFrequencytoAidRx

applications.

BandCompliance

TheLM3253operatesinconstantfrequencyPulse

•OperatesFromaSingleLi-ionCell

WidthModulation(PWM)modeproducingasmall

(2.7Vto5.5V)

andpredictableamountofoutputvoltageripple.This

•ACBReducesInductorRequirementsandSize

enablesbestECTELpowerrequirementsinGMSK

andEDGEspectralcompliance,withtheminimal

•MinimumTotalSolutionSizebyUsingSmall

amountoffilteringandexcessheadroom.When

FootprintandCaseSizeInductorand

operatinginPulseFrequencyModulation(PFM)

Capacitors

mode,theLM3253enablesthelowestDG09current

•16-bumpThinDSBGAPackage

consumptionandthereforemaximizessystem

•CurrentandThermalOverloadProtection

efficiency.

TheLM3253hasauniqueActiveCurrentassistand

APPLICATIONS

analogBypass(ACB)featuretominimizeinductor

sizewithoutanylossofoutputregulationforthe

•USBDatacards

entirebatteryvoltageandRFoutputpowerrange,

•CellularPhones

untildropout.ACBprovidesaparallelcurrentpath,

•Hand-HeldRadios

whenneeded,tolimitthemaximuminductorcurrent

•RFPCCardsto1.84A(typ.)whilestilldrivinga3Aload.TheACB

alsoenablesoperationwithminimaldropoutvoltage.

•Battery-PoweredRFDevices

TheLM3253isavailableinasmall2mmx2mm

chip-scale16-bumpDSBGApackage.

WhenconsideringtheuseoftheLM3253inasystem

design,contacttheTexasInstrumentsSalesorField

Applicationengineerforacopyofthe"LM3253:

DC-DCConverterfor3G/4GRFPAsPCBLayout

Considerations.”

1

Pleasebeawarethatanimportantnoticeconcerningavailability,standardwarranty,anduseincriticalapplicationsof

TexasInstrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.

2Alltrademarksarethepropertyoftheirrespectiveowners.

PRODUCTIONDATAinformationiscurrentasofpublicationdate.

Copyright©2012–2013,TexasInstrumentsIncorporated

ProductsconformtospecificationsperthetermsoftheTexas

Instrumentsstandardwarranty.Productionprocessingdoesnot

necessarilyincludetestingofallparameters.

Product specificaties