MT6752 Power Deliver NetworksWord下载.docx

MT6752 Power Deliver NetworksWord下载.docx

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RXD

RFIQandBSIControl

SPIandAUDI/F

DVDD_DVFS

LDOSandBucks

I2CandBC1.1

TRX

Figure1VBATPowerdelivernetwork

Powerpathmanagementforsystemload

MT6752solutionuseaexternalpowermanagementICtofinishsystempowerpathmanagementfrombatteryorchargersource.Asitshowsinthefigure2,therearedifferentpathtosystemloadwhensystempowersourcechangesfrombatterytocharger.

ThefirstpathisthatbatteryoutputpowertosystemloadwhenVBAT>

3.6V.ThePFETisonopendrainstate（VGS=0V）withoutbattery,whenbatterypluginbutnotchargerinPFETturnonandsystempowersourcedfrombattery.Atthetime,systemloadcurrentpathisISYS’,VSYS=VBAT.

Ifthebatteryvoltagefallsto3.5V,atthetimethechargerpluginaspowersouce,VSYSisregulatedto3.6Vtomaintainthesystemoutputevenwithadeeplydischargedorabsentbattery.Inthismode,theVSYSvoltageisregulatedbythebuckconverterandthebatteryPFETislinearlyregulatedtoregulatethechargecurrentintothebattery.ThecurrentfromthesupplyissharedbetweenchargingthebatteryandpoweringthesystemloadatVSYS.AsshowonFigure2,IIN=ISYS+IBAT.

Thedynamicpowerpathmanagement（DPPM）circuitrymonitorsthecurrentlimitscontinuouslyandiftheVBATfallsto3.5V,itadjustschargecurrenttomaintaintheminimumsystemvoltageandsupplytheloadonVSYS.Ifthechargecurrentisreducedtozeroandtheloadincreasesfurther，itenterthesupplementmode.Duringthesupplementmode.PFETisturnedonwhilethebatterysupplementsthesystemload.

IBAT

ISYS’

ISYS

IIN

Figure2Powerpathofsystemload

Figure3ExampleDPPMResponse（VSupply=5V,VBAT=3.1V,1.8AInputcurrentlimit）

BatteryConnected

Whenthebatteryisconnectedwithnoinputsource,thebatteryFETisturnedon.AfterthebatteryrisesaboveVBATUVLO=2.4V~2.6Vandthedeglitchtime,tDGL（BAT）=1.2ms,theVSYSoutputstartstorise.Inthismode,thecurrentisnotregulated;

however,thereisashortcircuitcurrentlimit.Iftheshortcircuitlimit（ILIM（DISCHG）=4~6A）isreachedforthedeglitchtime（tDGL（SC）=250us）,thebatteryFETisturnedofffortherecoverytime（tREC（SC）=2S）.Aftertherecoverytime,thebatteryFETisturnedontotestandseeiftheshorthasbeenremoved.Ifithasnot,theFETturnsoffandtheprocessrepeatsuntiltheshortisremoved.ThisprocessprotectstheinternalFETfromovercurrent.

Fromfigure3tofigure5,Whenbatteryisremovedbutchargersourcesintosystemload,thereisaPWMsignaldutycycleisabout83%onBATpin,soVGSisabout0V,FETisonopendrainstate.Afterbatteryconnected,FETisturnedonandregulatedcurrenttobattery.

Figure3startupwithnobattery

Figure4BatteryDetection

Figure5BatteryRemoval

SystemBoostforUVLO

MT6752usesanexternalDC/DCconvertertoextendthebatteryrun-timeandovercomesinputcurrentandvoltagelimitationsofthepoweredsystem.Whenthebatteryisatagoodstateofcharge（above3.5V）,aintegratedNMOSswitchwouldturnonthepath（Figure6Greenline）toconnectsbatteryasLDOsandNFCpower.Ifthebatteryvoltagelowerthansystemminimumvoltage（below3.5V）,theNMOSswitchturnoffandenterintoboostmode（Figure6Blueline）toutilizethefullbatterycapacity.Asitshowinfigure6,theboostrequireitsminimuminputvoltageis2.3VanditextendthevoltagelimitationsofLDOsandNFCinputpower.

AsFigure6shows,ItneedstoaddaschottkybetweenVSYSandVOUT_SYS_BOOSTtoensureVSYSalwayspowerforLDOsandNFCpowerwhenDC/DCconverterstartsup

Figure6Systemlowvoltageboostcircuit

2.CPUcorepower

2phaseBuckforAPcore

AexternalDC/DCisaddtosupplypowerofMT6752APcoresandimplementsDVFS，thevoltagerangeis0.6V~1.31V.Asitshowsinfigure7,theexternalDC/DChas2phasebucksconnectedtoMT6752APcorepowertorunDVFSfunctionforlowpowercondition.WhenCPUslowdown,thepowerlevelwillstepdownaccordingtocorefrequency.WhenCPUcoreswouldbeactive,buckconvertorrisespowerlevelatfirstandthenCPUcoresfrequencystepup.

ThepowerlevelofbuckconvertorisprogrammedbyI2Cbus,asitshowsonfigure7itprogramsthedividerresistanceonconvertorfeedbackcircuittosetvoltagelevel.

Figure72PhaseBuck

AsFigure8,itistheexampleofoutputvoltagedifferentialsensing.ThedifferentialsensecomparesahighaccuracyVIDDACandaprecisionreferencetoimplementalowoffseterroramplifier.Thismaintainsaworst-casespecificationof±

9.5mVdifferentialsensingerrorovertheirfulloperatingoutputvoltageandtemperaturerange.TheoutputvoltageissensedbetweentheFBpinandtheFBRTNpin.FBshouldbeconnectedtotheregulationpoint,usuallytheremotesensepinofthemicroprocessor.FBRTNshouldbeconnecteddirectlytotheremotesensegroundpoint.TheinternalVIDDACandprecisionreferencearereferencedtoFBRTN,whichhasaminimalcurrentof100μAtoallowaccurateremotesensing.TheinternalerroramplifiercomparestheoutputoftheDACtotheFBpintoregulatetheoutputvoltage.

Figure.8AExampleofFeedbackCircuit

ModemCorePowerandGPUpower

MT6325internalbuckconvertorVCORE1/2andVGPU,supplypowerforModemcoreandGPUcore.

Thebuckconvertorsuseaproprietarynon-linear,fixed-frequencyPWMmodulatortodeliverafastloadtransientresponse,whilemaintainingaconstantswitchingfrequencyoverawiderangeofoperatingconditions.Althoughthistypeofoperationnormallyresultsinaswitchingfrequencythatvarieswithinputvoltageandloadcurrent,aninternalfrequencyloopholdstheswitchingfrequencyconstantoveralargerangeofinputvoltagesandloadcurrents.Forverylightload,buckconvertoroperatesinDiscontinuousCurrentDiode（DCM）single-pulsePFM,whichproduceslowoutputripple.TransitionbetweenPWMandPFMisrelativelyseamless,providingasmoothtransitionbetweenDCCMandCCMModes.

Whileloadcurrentisbelow100mA,lightloadcondition,convertorsgointoPFMandtransittoPWMwhenloadcurrentisabove100mA.FromFigure8andFigure9,theouputrippleisabout0.75MHZ~2MHZ,rippleswingisabout20mVinPFMmodewhenVintransitsbetween3Vto3.6Vandloadcurrenttransitbetween500mAto50mA.

Figure9.3Vto3.6VVinTransientcombinedwith500mAto50mALoadTransient

Figure10.3.6Vto3VVinTransientcombinedwith50mAto500mALoadTransient

Fromfigure10andfigure11,loadcurrentis200mAand800mA,heavyloadcondition,convertorsenterPWMmode,theoutputvoltageissmoothandwithnoripple.

Figure11.3Vto3.6VVinTransientcombinedwith800mAto200mALoadTransient

Figure12.3Vto3.6VVinTransientcombinedwith200mAto800mALoadTransient

AutoPFM/PWMtransitionishigherefficiencythanforcedPWMthroughfromlightloadtoheavyloadofsystem.Especially,PFMmodegivesconvertorahighefficiencyonlightload.

Figure13．Efficency，AutoPWM/PFMvs.ForcedPWMatVout=0.75V

Figure14．Efficency，AutoPWM/PFMvs.ForcedPWMatVout=1.2V

3.MemoryPower

InternalSRAMpower

BBhasinternalSRAMforoperationbuffer.DVDD_SRAMsuppliesthepowerfortheinternalSRAMpower.

DDRpowernetwork

VIO18_PMU（1.8V）suppliesDDRcore1power.VDRAM_PMU（1.1V/1.2V/1.35V/1.5V,2000mA）suppiesDDRcoreandI/OpowerofBB.Alsoitsuppliescore2powerandI/Ovoltage,CAcontrollerofDDR.

eMMCpowernetwork

VEMC_3V3_PMU（3/3.3V,400mA）supplieseMMCcorevoltageofeMCP，whichisNANDintegratedwithacontrollerforeMMCboot.VIO18_PMU（1.8V）supplieseMMCI/OvoltageonbothBBandeMCPside.AndalsoVIO18_PMUsuppliesMSDC0controllerpowerofBB.

VMC（1.8V/3.3V,200mA）suppliesMSDC1controllerandI/OvoltageofBBside.VMCH（3/3.3v,800mA）suppliescoreandI/Opowerofexternalmemorycard.Fromfigure15,VCCQ（I/OVoltage）doesnotsupport3.3VrangeWheneMMCbusclockspeedis200MHZ.

Figure15eMMCvoltagecombinationsfromJEDEC

4.RFPower

Thereare5powersforRFtransceiverandPA,VRF18_PMU（1.825V,450Ma）forMT6169,VRF18_1_PMU（1.825V,200mA）forMT6165.VPA_PMU（0.5V~3.4V,600mA）suppliesforSKY77621Whichisahybridmultimodemultiband（MMMB）PowerAmplifierModule（PAM）thatsupports2.5G/3G/4Ghandsets,andoperatesefficientlyinGSM,EGPRS,EDGE,WCDMA,TD-SCDMA,andLTEmodes.AndalsoVPA_PMUsuppliesforSKY77778,WhichisPowerAmplifierModuleforLTEFDDBand7（2500–2570MHz）,andTDDBands38/41（2496–2690MHz）,Band40（2300–2400MHz）,AXGPBand（2545–2575MHz）.VTCXO_1_PMU（2.8V,40mA）suppliespowerforMT616926Mclockblock.VTCXO_2_PMU（2.8V,40mA）suppliespowerforMT616526Mclockblock.