Texas Instruments LM3253 Handleiding
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LM3253
www.ti.com
SNVS791Q–FEBRUARY2012–REVISEDMAY2013
LM3253High-CurrentStep-DownConverterfor2G/3G/4GRFPowerAmplifiers
CheckforSamples:LM3253
1
FEATURES
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•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
| Merk: | Texas Instruments |
| Categorie: | Niet gecategoriseerd |
| Model: | LM3253 |
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