矽力杰 Silergy SY8851B 2.0-5.5V 输入 0.5A 输出高效同步降压稳压器 规格书 (Datasheet)佰祥电子

SY8851B

400nAultralowIQ,1.0MHz,500mA

SynchronousStepDownRegulator

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GeneralDescriptionFeatures

TheSY8851Bisa400nAultralowquiescentcurrent,2.0~5.5VInputVoltageRange

1.0MHzsynchronousstepdownDC/DCregulator,whichUltraLowQuiescentCurrentDownto400nA

iscapableofdeliveringupto500mAoutputcurrent.ItcanLowRDS(ON)forInternalSwitches(Top/Bottom)

operateoverawideinputvoltagerangefrom2.0Vto5.5V280mΩ/120mΩ

andintegratemainswitchandsynchronousswitchwithInstantPWMControltoAchieveUltraFast

verylowRDS(ON)tominimizetheconductionloss.LoadTransientSpeed.

HighSwitchingFrequency1.0MHzMinimizes

Lowoutputvoltageripple,smallexternalinductorandtheExternalComponents

capacitorsizesareachievedwith1.0MHzswitchingInternalSoft-startLimitstheInrushCurrent

frequency.PowerGoodIndicator

HiccupModeforOutputShortCircuitProtection

OrderingInformation100%DropOutOperation

OutputAutoDischargeFunction

SY8851□(□□)□RoHSCompliantandHalogenFree

TemperatureCodeCompactPackage:DFN2×2-8

PackageCode

OptionalSpecCodeApplications

OrderingNumberPackagetypeNote

SY8851BDFCDFN2×2-8--BatteryPoweredApplications

ConsumerandPortableMedicalProducts

PersonalWareProducts

TypicalApplications

Efficiencyvs.OutputCurrent

(IOUT=0~500mA,L=2.2µH/0420CDMCCDS-2R2MC)

100

L：2.2µH

VIN:2.0V~5.5VVOUT:1.8V

VINLX90

CRCffC)

INRPGOUTHOUT

10MΩ10pF10µF/6.3V%

100k(

80

10µF/6.3Vy

c

PGFBn

e

i

c

i

ENf70

f

RLE

STB20MΩ

GND

60

VIN=3.6V,VOUT=3.3V

VIN=5.0V,VOUT=3.3V

50

0.0010.010.1110100500

OutputCurrent(mA)

Figure1.SchematicDiagramFigure2.Efficiencyvs.OutputCurrent

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SY8851B

Pinout(TopView)

VIN18LX

PG27GND

Paddle

OUT36EN

FB45STB

(DFN2×2-8)

TopMark:tTxyz(devicecode:tT,x=yearcode,y=weekcode,z=lotnumbercode)

PinNamePinNumberPinDescription

Powerinputpin.DecouplethispintoGNDpinwithatleasta10µFceramic

VIN1

capacitor.

Powergoodindicator(opendrainoutput).Lowiftheoutput<90%ofregulation;

PG2

highotherwise.Connectapull-upresistortotheinput.

OUT3Outputvoltagefeedbackpin.Connectthispintotheoutputside.

Connectthispintothecenterpointoftheoutputresistordivider(asshownin

FB4

Figure1)toprogramtheoutputvoltage:VOUT=1.2V×(1+RH/RL).

Thispincontrolsthestandbymode.

STB5WithSTB=low,deepstandbyfunctionisactivated,IQ=400nA.

WithSTB=high,deepstandbyfunctionisdisabled,IQ=15uA.

EN6Enablecontrol.Pullhightoturnon.Donotleaveitfloating.

GND7PowerGroundpin.

LX8Inductorpin.Connectthispintotheswitchingnodeofinductor.

AbsoluteMaximumRatings(Note1)

SupplyInputVoltage--------------------------------------------------------------------------------------------0.3Vto6.0V

PG,OUT,STB,EN-----------------------------------------------------------------------------------------0.3VtoVIN+0.6V

LXVoltage----------------------------------------------------------------------------------------------0.3V（*1）to6.0V（*2）

PowerDissipation,PD@TA=25°C,

DFN2×2-8----------------------------------------------------------------------------------------------------1.1W

PackageThermalResistance(Note2)

θJA-------------------------------------------------------------------------------------------------------------85°C/W

JC-------------------------------------------------------------------------------------------------------------45°C/W

JunctionTemperatureRange---------------------------------------------------------------------------------40°Cto150°C

LeadTemperature(Soldering,10sec.)---------------------------------------------------------------------------------260°C

StorageTemperatureRange-----------------------------------------------------------------------------------65°Cto150°C

(*1)LXVoltageTestedDownto-3V<40ns

(*2)LXVoltageTestedUpto+7V<40ns

RecommendedOperatingConditions(Note3)

SupplyInputVoltage---------------------------------------------------------------------------------------------2.0Vto5.5V

JunctionTemperatureRange---------------------------------------------------------------------------------40°Cto125°C

AmbientTemperatureRange----------------------------------------------------------------------------------40°Cto85°C

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SY8851B

ElectricalCharacteristics

(VIN=5.0V,VOUT=1.8V,L=2.2µH,COUT=10µF,TA=25°C,unlessotherwisespecified)

ParameterSymbolTestConditionsMinTypMaxUnit

InputVoltageRangeV2.05.5V

IN

InputUVLOThresholdV1.81.95V

UVLO

InputUVLOHysteresisV0.15V

HYS

VFB=VREF×115%,STB=0400600nA

QuiescentCurrentIQ

V=V×115%,STB=115µA

FBREF

ShutdownCurrentIV=0V10100nA

SHDNEN

FeedbackReferenceVoltageV1.1821.21.218V

REF

LXNodeDischargeResistanceR10Ω

DIS

TopFETRR280mΩ

ONDS(ON)1

BottomFETRR120mΩ

ONDS(ON)2

ENInputVoltageHighV1.1V

EN,H

ENInputVoltageLowV0.4V

EN,L

PowerGoodThresholdVVrising(good)90%V

PGFBREF

PowerGoodDelaytHightolow20µs

PG,F

MinONTimet80ns

ON,MIN

MaximumDutyCycleD100%

MAX

fromENhightoLXstart

TurnOnDelayt600µs

ON,DLYswitching

SwitchingFrequencyfV=1.2V,I=500mA1MHz

SWOUTOUT

TopFETCurrentLimitI0.91.5A

LMT,TOP

BottomFETCurrentLimitI0.5A

LMT,BOT

OutputUnderVoltageProtection

VVthreshold1V

ThresholdUVP.OUTOUT

OutputUVPDelayt20µs

UVP,DLY

UVPHiccupONTimet0.25ms

UVP,ON

UVPHiccupOFFTimet0.25ms

UVP,OFF

ThermalShutdownTemperatureT150ºC

SD

ThermalShutdownHysteresisT15ºC

HYS

Note1:Stressesbeyondthe“AbsoluteMaximumRatings”maycausepermanentdamagetothedevice.Theseare

stressratingsonly.Functionaloperationofthedeviceattheseoranyotherconditionsbeyondthoseindicatedinthe

operationalsectionsofthespecificationisnotimplied.Exposuretoabsolutemaximumratingconditionsfor

extendedperiodsmayaffectdevicereliability.

Note2:θJAofSY8851BDFCismeasuredinthenaturalconvectionatTA=25°Con2OZtwo-layerSilergy

evaluationboardofJEDEC51-3thermalmeasurementstandard.PaddleofDFN2x2-8packageisthecaseposition

forSY8851BDFCθJCmeasurement.

Note3:Thedeviceisnotguaranteedtofunctionoutsideitsoperatingconditions.

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SY8851B

TypicalPerformanceCharacteristics

Efficiencyvs.OutputCurrentEfficiencyvs.OutputCurrent

(IOUT=0~500mA,L=2.2µH/0420CDMCCDS-2R2MC)(IOUT=0~500mA,L=2.2µH/0420CDMCCDS-2R2MC)

100100

90

85

))80

%

%

(

(

70

y

y

c

c

nn70

e

e

i

i

c

c

i

i

f55f

f

f

EE60

VIN=3.3V,VOUT=1.2VVIN=3.3V,VOUT=1.8V

40

VIN=4.2V,VOUT=1.2V50VIN=4.2V,VOUT=1.8V

VIN=5.0V,VOUT=1.2VVIN=5.0V,VOUT=1.8V

2540

0.0010.010.11101005000.0010.010.1110100500

OutputCurrent(mA)OutputCurrent(mA)

Efficiencyvs.OutputCurrentOutputRipple

(IOUT=0~500mA,L=2.2µH/0420CDMCCDS-2R2MC)(VIN=5.0V,VOUT=1.8V,IOUT=500mA)

100

∆VOUT20mV/div

90

)

%

(

80

yVLX5V/div

c

n

e

i

c

i

f70

f

IL500mA/div

E

60

VIN=3.6V,VOUT=3.3V

VIN=5.0V,VOUT=3.3V

50

0.0010.010.1110100500

Time(2µs/div)

OutputCurrent(mA)

LoadTransientLoadTransient

(VIN=5V,VOUT=1.8V,STB=0,IOUT=0.5mA~500mA)(VIN=5V,VOUT=1.8V,STB=1,IOUT=0.5mA~500mA)

△VOUT50mV/div△VOUT50mV/div

IL500mA/divIL500mA/div

Time(100μs/div)Time(100μs/div)

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SY8851B

StartupfromEnableShutdownfromEnable

(VIN=5.0V,VOUT=1.8V,IOUT=500mA)(VIN=5.0V,VOUT=1.8V,IOUT=500mA)

EN5V/divEN5V/div

VOUT2V/divVOUT5V/div

VLX5V/divVLX5V/div

IL500mA/divIL500mA/div

Time(400μs/div)Time(400μs/div)

ShortCircuitProtectionShortCircuitProtection

(VIN=5.0V,VOUT=1.8V,ILOAD=0A~Short)(VIN=5.0V,VOUT=1.8V,ILOAD=500mA~Short)

VOUT2V/divVOUT2V/div

IL500mA/divIL500mA/div

Time(400µs/div)Time(400µs/div)

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SY8851B

V(1V/V)OUTOUTIN,MAX

OperationL

TheSY8851Bisahighefficiency1.0MHzfI40%SWOUT,MAX

synchronousstepdownDC/DCregulator,whichisWherefSWistheswitchingfrequencyandIOUT,MAXis

capableofdeliveringupto500mAoutputcurrents.Itthemaximumloadcurrent.

canoperateoverawideinputvoltagerangefrom

2.0Vto5.5Vandintegratemainswitchand2)Thesaturationcurrentratingoftheinductormust

synchronousswitchwithverylowRDS(ON)tobeselectedtobelargerthanthepeakinductor

minimizetheconductionloss.currentunderfullloadconditions.

Lowoutputvoltageripple,smallexternalinductor

andcapacitorsizesareachievedwith1.0MHzVOUT(1-VOUT/VIN,MAX)

ISAT,MINIOUT,MAX

switchingfrequency.2fSWL

ApplicationsInformation3)TheDCRoftheinductorandthecorelossatthe

BecauseofthehighintegrationintheSY8851B,theswitchingfrequencymustbelowenoughtoachieve

applicationcircuitbasedonthisregulatorisratherthedesiredefficiencyrequirement.Itisdesirableto

chooseaninductorwithDCR<25mΩtoachievea

simple.OnlyinputcapacitorCIN,outputcapacitor

C,outputinductorL,feedbackresistors(Randgoodoverallefficiency.

OUTH

RL)andfeed-forwardcapacitorCffneedtobeselected

forthetargetedapplicationspecifications.Inductorvs.OutputCapacitor

TheinstantPWMcontrolstrategyneedsverylittle

COUTtoconfirmstability.Toolargeinductorand

FeedbackResistorDividersRHandRL

COUTwillbeleadtounstable.Therecommend

ChooseRHandRLtoprogramtheproperoutput

voltage.Tominimizethepowerconsumptionunderinductanceandoutputcapacitorisshownasbelow.

lightloads,itisdesirabletochooselargeresistance

Inductancevs.OutputCapacitorSelectionTable

valuesforbothRHandRL.Avaluebetween10MΩ

and50MΩishighlyrecommendedforbothresistors.COUT

L

IfRL=20MΩischosen,thenRHcanbecalculatedto10µF22µF80µF120µF350µF

be:

2.2µH√√√√√

(VOUT1.2V)RL

RH

1.2V

4.7µH√√√√×

Feed-forwardCapacitorCff

Feed-forwardcapacitorisrequiredtoachievegood6.8µH√√√××

stabilityandfastdynamicresponse.Atleasta10pF

ceramiccapisrecommendedfortheapplication.

OCPandSCPProtectionMethod

InputCapacitorCINWithloadcurrentincreasing,assoonasthehighside

AtypicalX5RorabettergradeceramiccapacitorFETcurre