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KC1510说明书.docx

KC1510说明书

GeneralDescription

KC1510isavoltagemode,step-downDC-DCconverterthatisdesignedtomeet3Aoutputcurrent,andutilizesPWMcontrolschemethatswitcheswith310KHZfixedfrequency.

TheinputvoltagerangeofKC1510isfrom3.6Vto25V,andavailableinadjustableoutputvoltagefrom0.8VtoVin.Thesupplycurrentis

Only3mAduringoperationandunder1uAinshutdown.

Thisdeviceprovidesanenablefunctionthatandbecontrolledbyexternallogicsignal.Italsoprovidesexcellentregulationduringlineorloadtransient.Otherfeaturesofcurrentlimit,thermalshutdownprotection,andshortcircuitprotectionarealsoincluded.DuetothelowRds（ON）oftheinternalpowerMOSFET,thisdeviceprovideshighefficiencystep-downapplication.Itcanalsooperatewithamaximumdutycycleof100%foruseinlowdrop-outconditions.ThepackageisavailableinstandardSOP-8L.

OrderingInfornation

KC15101234

1（PackageType）=>J:

SOP

2（NumberofPins）=>G:

8pin

3（OutputVoltage）=>Blank:

Adjustable

4（SpecialFeature）=>Blank:

N/A

AvailablePartNumber

KC1510JG

Features

●3.6Vto28VInputVoltageRange

●AdjustableOutputVoltagefrom0.8Vto23V

●Upto95%Efficiency

●Continuous3AOutputCapability

●310KHZOscillationFrequency

●0.8VReferenceVoltage

●1uALowShutdownCurrent

●3mALowSupplyCurrent

●100%DutyCycle

●Built-inLowRds（on）PowerMOSFET

●NoExternalCompensationRequired

●SupportLowESROutputCeramicCapacitors

●AdjustableCurrentLimit

●ShortCircuitandThermalProtection

●SOP-8LPb-FreePackage

Applications

●BroadbandCommunicationDevice

●LCDTV/Monitor

●StorageDevice

●WirelessApplication

●PrinterandotherPeripheralEquipment

●ADSLModem

●PCMotherboard

MarkingInformation

12（DateCode）

Fordatecoderule,pleasecontactoursalesrepresentativedirectly

34（Internalcode）

TypicalApplication

●12Vto5V/3Awith10uFLowESRCeramicCapacitor

●5Vto1.8V/3Awith330uFElectrolyticCapacitor

EfficiencyCurve

QuickDesignTable

（1）

ForE/Capplication,Iload=3A,ΔIL=0.6A,continuouscurrentmodeoperation.

L1:

RecommendedInductorR2:

OutputVoltageDivider

R1:

OutputVoltageDividerR3:

CurrentLimitSettingResistor

Vin

Vout

12V

18V

1.2V

L1:

6.8uH

R1:

1.5KΩ

R2:

3KΩ

R3:

5.6KΩ

L1:

8.2uH

R1:

1.5KΩ

R2:

3KΩ

R3:

3KΩ

1.5V

L1:

8.2uH

R1:

1.3KΩ

R2:

1.5KΩ

R3:

5.6KΩ

L1:

10uH

R1:

1.3KΩ

R2:

1.5KΩ

R3:

3KΩ

L1:

10uH

R1:

1.3KΩ

R2:

1.5KΩ

R3:

3KΩ

1.8V

L1:

8.2uH

R1:

25KΩ

R2:

2KΩ

R3:

5.6KΩ

L1:

10uH

R1:

2.5KΩ

R2:

2KΩ

R3:

3KΩ

L1:

12uH

R1:

2.5KΩ

R2:

2KΩ

R3:

3KΩ

2.5V

L1:

10uH

R1:

4.7KΩ

R2:

2.2KΩ

R3:

5.6KΩ

L1:

15uH

R1:

4.7KΩ

R2:

2.2KΩ

R3:

3KΩ

L1:

15uH

R1:

4.7KΩ

R2:

2.2KΩ

R3:

2.7KΩ

L1:

15uH

R1:

4.7KΩ

R2:

2.2KΩ

R3:

2.5KΩ

3.3V

L1:

12uH

R1:

4.7KΩ

R2:

1.5KΩ

R3:

5.6KΩ

L1:

15uH

R1:

4.7KΩ

R2:

1.5KΩ

R3:

3KΩ

L1:

18uH

R1:

4.7KΩ

R2:

1.5KΩ

R3:

2.7KΩ

L1:

22uH

R1:

4.7KΩ

R2:

1.5KΩ

R3:

2.5KΩ

L1:

18uH

R1:

6.8KΩ

R2:

1.3KΩ

R3:

3KΩ

L1:

22uH

R1:

6.8KΩ

R2:

1.3KΩ

R3:

2.7KΩ

L1:

27uH

R1:

6.8KΩ

R2:

1.3KΩ

R3:

2.5KΩ

L1:

36uH

R1:

10.2KΩ

R2:

1KΩ

R3:

3KΩ

L1:

33uH

R1:

10.2KΩ

R2:

1KΩ

R3:

2.7KΩ

12V

L1:

36uH

R1:

18.2KΩ

R2:

1.3KΩ

R3:

2.7KΩ

QuickDesignTable

（2）

ForE/Capplication,Iload=3A,ΔIL=0.6A,continuouscurrentmodeoperation.

L1:

RecommendedInductorR2:

OutputVoltageDivide

C1:

Feed-ForwardCapacitorR3:

CurrentLimitSettingResistor

R1:

OutputVoltageDivider

Vin

Vout

12V

18V

2.5V

L1:

15uH

C1:

470pF

R1:

4.7KΩ

R2:

2.2KΩ

R3:

5.6KΩ

L1:

27uH

C1:

470pF

R1:

4.7KΩ

R2:

2.2KΩ

R3:

3KΩ

3.3V

L1:

8.2Uh

C1:

470pF

R1:

4.7KΩ

R2:

1.5KΩ

R3:

5.6KΩ

L1:

15uH

C1:

470pF

R1:

4.7KΩ

R2:

1.5KΩ

R3:

3KΩ

L1:

18uH

C1:

470pF

R1:

6.8KΩ

R2:

1.3KΩ

R3:

3KΩ

L1:

22uH

C1:

470pF

R1:

6.8KΩ

R2:

1.3KΩ

R3:

2.7KΩ

L1:

36uH

C1:

470pF

R1:

10.2KΩ

R2:

1KΩ

R3:

3KΩ

L1:

33uH

C1:

470pF

R1:

10.2KΩ

R2:

1KΩ

R3:

2.7KΩ

12V

L1:

36uH

C1:

470pF

R1:

18.2KΩ

R2:

1.3KΩ

R3:

2.7KΩ

FunctionalBlockDiagram

PinConfigurations

PinNo.

Name

Description

Thispinsensesthefeedbackvoltagetoregulatetheoutputvoltage.Connectthispintoavoltagedividertosettheoutputvoltage

Thispinallowsanexternalcontrolsignaltoturn-on/offthisdevice.Floatthispinorforceitbelow0.8Vtoturn-offthisdevice,forceitabove2Vtoturn-onthisdevice.Ifthisfeatureisnotneeded,connectthispintoINdirectly

OCSET

AddanexternalresistorfromthispintoINtosetcurrentLimit

Theinputpinofthestep-downConverter

AsuitablylargecapacitormustbeconnectedfromthispintogroundtobypassnoiseontheinputoftheIC

5,6

Theoutputpinofthestep-downconverter

Thispinistheswitchingnodethatsuppliespowertotheoutput,connectaLCfilterfromthispintotheoutputloadandarectifierdiodetotheground

7,8

GND

Thegroundpinofthestep–downconverter

Connectthispinthecircuitground.

AbsoluteMaximumRatings

Parameter

Rating

InputVoltage

28V

SWpinVoltageRange

-0.5V~Vin+0.5V

FBpinVoltageRange

-0.3V~Vin

EnpinVoltageRange

-0.3V~Vin+0.3V

StorageTemperatureRange

-65℃~150℃

JunctionTemperature

150℃

LeadSolderingTemperature（10sec）

300℃

Thesearestressratingonlyandfunctionaloperationisnotimplied.Exposuretoabsolutemaximumratingsforprolongedtimeperiodsmayaffectdevicereliability.Allvoltagearewithrespecttoground.

RccommendedOperatingCondition

Parameter

Rating

InputVoltageRange

3.6V~28V

AmbienttemperatureRange

-40℃~85℃

JunctionTemperatureRange

-40℃~125℃

Theseareconditionsunderwhichthedevicefunctionsbutthespecificationsmightnotbeguaranteed.Forguaranteedspecificationsandtestconditions,pleaseseetheElectricalspecifications.

PackageInformation

Parameter

Package

Symbol

Rating

ThermalResistance

（JunctiontoCase）

SOP-8L

ΘJC

20℃/W

ThermalResistance

（JunctiontoAmbient）

ΘJA

60℃/W

ElectricalSpecifications

Vin=12V,Voutsetto5V,Ta=25℃,unlessotherwisenoted.

Symbol

Parameter

TestCondition

Min

Typ

Max

Units

VIN

InputVoltage

3.6

VFB

FeedbackVoltage

Iload=0.1A

0.8

Isw

SwitchCurrent

3.5

Efficiency

Vin=12V,Vout=5V,Iload=3A

Vin=5V,Vout=3.3V,Iload=3A

Fosc

OscillationFrequency

300

340

380

KHZ

FSCP

Frequencyofshort

CircuitProtection

KHZ

DutyCycle

Vfb=0V

100

Vfb=1.5V

Rds（ON）

InternalMOSFETONResistance

Vin=5V,VFB=0V

mΩ

Vin=12V,VFB=0V

SupplyCurrent

VFB=1.5V

ISD

ShutdownCurrent

VEN=0V

VEN

ENpininput

ThresholdVoltage

RegulatorOFF

1.3

0.8

RegulatorON

2.0

IEN

ENpinBiasCurrent

RegulatorOFF

RegulatorON

Ifb

FBpinBiasCurrent

Iload=0.2A

0.1

0.5

Iocset

OCSETPinBias

Current

Iload=0.2A

110

ΔVLine

LineRegulation

Vin=3.6V~25V

ΔVLoad

LoadRegulation

Iload=0.2A~3A

0.2

0.5

TSD

OverTemperature

Shutdown

145

℃

THYS

OverTemperature

ShutdownHysteresis

℃

TypicalperformanceCharacteristics

Vin=12V,Voutsetto3.3V,Ta=25℃,unlessotherwisenoted.

TypicalperformanceCharacteristics（Contd.）

ApplicationInformation

PWMControl

TheKC1510consistsofDC/DCconvertersthatemployapulse-widthmodulation（PWM）system.

InconvertersoftheKC1510,thepulsewidthvariesinarangefrom0to100%,accordingtotheloadcurrent.Theripplevoltageproducedbytheswitchingcaneasilyberemovedthroughafilterbecausetheswitchingfrequencyremainsconstant.Therefore,theseconvertersprovidealow-ripplepoweroverbroadrangesofinputvoltageandloadcurrent.

OutputVoltageProgramming

KC1510developsaband-gapbetweenthefeedbackpinandgroundpin.Therefore,theoutputvoltagecanbeformedbyR1andR2.Use1%metalfilmresistorsforthelowesttemperaturecoefficientandthebeststability.Selectlowerresistorvaluetominimizenoisepickupinthesensitivefeedbackpin,orhigherresistorvaluetoimproveefficiency

Theoutputvoltageisgivenbythefollowingformula.

Vout=VFBx（1+R1/R2）whereVFB=0.8V

ShortCircuitProtection

Whentheoutputisshortedtoground,theprotectioncircuitwillbetriggeredandtheoscillationfrequencydowntoapproximately40KHZ.Theoscillationfrequencywillreturnto310KHZoncetheoutputvoltageorthefeedbackvoltagerisesabove0V.

CurrentLimitSetting

ThisdevicereservesOCSETpintosettheswitchingpeakcurrent.Ingeneral,thepeakcurrentmustbe1.5timesofthecontinuousoutputcurrent.Itcanbecalculatedasbelow:

ICL=（IOCSETxROCSET）/RDS（ON）

WhereICListhecurrentlimit,IOCSETistheOCSETbiascurrent（90uATyp.）,andRDS（ON）istheON-resistanceoftheinternalpowerMOSFET.

Delaystart-up

ThefollowingcircuitusestheENpintoprovideatimedelaybetweentheinputvoltageisappliedandtheoutputvoltagecomesup.Astheinstantoftheinputvoltagerises,thechargingofcapacitorCDELAYpullstheENpinlow,keepingthedeviceoff.OncethecapacitorvoltagerisesabovetheEnpinthresholdvoltage,thedevicewillstarttooperate.Thestart-updelaytimecanbecalculatedbythefollowingformula:

VINx（1–e-T/（RxC））>VEN

WhereTisthestart-updelaytime,RisRDALAY,CisCDALAY,andthetypicalVENis1.3V.Thisfeatureisusefulinsituationswheretheinputpowersourceislimitedintheamountofcurrentitcandeliver.Itallowstheinputvoltagetorisetoahighervoltagebeforethedevicestartsopera

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