LED驱动电源厂家只需要将电流感测电阻R8的值减半

PowerInt公司的LinkSwitch-PH系列集成了725V功率MOSFET,连续模式PWM控制器,用于自偏置的高压开关电流源,频率抖动,逐个周期的电流限制以及延迟热关断电路,大大地简化PF大于0.9,TRIAC调光的LED驱动器的设计,主要用在离线led驱动器.本文介绍了LinkSwitch-PH系列主要特性,功能方框图,TRIAC调光14W和7WLED驱动器电路图,以及TRIAC调光14WLED驱动器参考设计主要指标,电路图和材料清单(BOM).

TheLinkSwitch-PHdramaticallysimplifiesimplementationofLEDdriversrequiringPF>0.9,TRIACdimmercapabilityandhighefficiency.Thesingle-stagePFandconstantcurrentcontrollerELiminatespassivecircuitryrequiredforpowerfactorcorrectionandelectrolyticbulkcapacitor.Theadvancedprimary-sidecontroltechniquesusedbytheLinkSwitch-PHdeviceprovideaccurateconstantcurrentcontrolwhileeliminatingtheneedforanoptocouplerandsecondary-sidecurrentcontrolcircuitry.

LinkSwitch-PHincorporatesa725VpowerMOSFET,acontinuous-modePWMcontroller,ahighvoltageswitchedcurrentsourceforselfbiasing,frequencyjittering,cycle-by-cyclecurrentlimitandhystereticthermalshutdowncircuitry,allinamonolithicIC.

LinkSwitch-PH系列主要特性:

DramaticallySimplifiesOff-lineLEDDrivers

?Flicker-freephase-controlledTRIACdimming

?Singlestagepowerfactorcorrectedandaccurateconstantcurrent(CC)output

?Eliminatesoptocouplerandallsecondarycurrentcontrolcircuitry

?Eliminatesallcontrolloopcompensationcircuitry

?Simpleprimary-sidePWMdimminginterface

?Universalinputvoltagerange

?Enablesdesignsthatareelectrolytic-free

AccurateandConsistentPerformance

?Compensatesfortransformerinductancetolerances

?Compensatesforlineinputvoltagevariations

?FrequencyjitteringgreatlyreducesEMIfiltersizeandcosts

AdvancedProtectionandSafetyFeatures

?Auto-restartforshort-circuitprotection

?Opencircuitfaultdetectionmode

?Automaticthermalshutdownrestartwithhysteresis

?MeetshighvoltagecreepagerequirementbetweenDRAINandallothersignalpinsbothonPCBandatpackage

EcoSmart?–EnergyEfficient

?LowstandbypowerremoteON/OFFfeature(<50mWat230VAC)

?Nocurrentsenseresistors–maximizesefficiency

?Highefficiencyoperation,>85%achievable

GreenPackage

?HalogenfreeandROHScompliantpackage

LinkSwitch-PH系列应用:

?Off-lineLEDdriver


图1.LinkSwitch-PH系列功能方框图

图2.LinkSwitch-PH系列TRIAC调光14WLED驱动器电路图

图3.LinkSwitch-PH系列TRIAC调光7WLED驱动器电路图

TRIAC调光14WLED驱动器参考设计

ReferenceDesignReportforaHighEfficiency(≥85%),HighPowerFactor(>0.9)TRIACDimmable14WTYPLEDDriverUsingLinkSwitch?-PHLNK406EG

参考设计主要特性和指标:
?
Superiorperformanceandenduserexperience

TRIACdimmercompatible(includinglowcostleadingedgetype)

Nooutputflicker

>1000:1dimmingrange

Cleanmonotonicstart-up–nooutputblinking

Faststart-up(<300ms)–noperceptibledelay

Consistentdimmingperformanceunittounit

Highlyenergyefficient

≥85%at115VAC,≥87%at230VAC

Lowcost,lowcomponentcountandsmallprintedcircuitboardfootprintsolution

Nocurrentsensingrequired

Frequencyjitterforsmaller,lowercostEMIfiltercomponents

Integratedprotectionandreliabilityfeatures

Outputopencircuit/outputshort-circuitprotectedwithauto-recovery

Lineinputovervoltageshutdownextendsvoltagewithstandduringlinefaults.

Auto-recoveringthermalshutdownwithlargehysteresisprotectsbothcomponentsandprintedcircuitboard

Nodamageduringbrown-outorbrown-inconditions
?
MeetsIEC61000-4-5ringwave,IEC61000-3-2ClassCharmonicsandEN55015BconductedEMI

Thedocumentdescribesahighpower-factorTRIACdimmableLEDdriverdesignedtodriveanominalLEDstringvoltageof28Vat0.5Afromaninputvoltagerangeof90VACto265VAC.TheLEDdriverutilizestheLNK406EGfromtheLinkSwitch-PHfamilyofICs.

LinkSwitch-PHICsallowtheimplementationofcosteffectiveandlowcomponentcountLEDdriverswhichbothmeetpowerfactorandharmonicslimitsbutalsoofferenhancedenduserexperience.Thisincludesultra-widedimmingrange,flickerfreeoperation(evenwithlowcostwithAClineTRIACdimmers)andfast,cleanturnon.

ThetopologyusedisanisolatedFlybackoperatingincontinuousconductionmode.Outputcurrentregulationissensedentirelyfromtheprimarysideeliminatingtheneedforsecondarysidefeedbackcomponents.NoexternalcurrentsensingisrequiredontheprimarysideeitherasthisisperformedinsidetheICfurtherreducingcomponentsandlosses.TheinternalcontrolleradjuststheMOSFETdutycycletomaintainasinusoidalinputcurrentandthereforehighpowerfactorandlowharmoniccurrents.

TheLNK406EGalsoprovidesasophisticatedrangeofprotectionfeaturesincludingautorestartforopencontrolloopandoutputshort-circuitconditions.Lineovervoltageprovidesextendedlinefaultandsurgewithstand,outputovervoltageprotectsthesupplyshouldtheloadbedisconnectandaccuratehystereticthermalshutdownensuressafeaveragePCBtemperaturesunderallconditions.

InanyLEDluminairethedriverdeterminesmanyoftheperformanceattributesexperiencedbytheendcustomer(user)includingstartuptime,dimming,flickerandunittounitconsistency.Forthisdesignafocuswasgiventocompatibilitywithaswiderrangeofdimmersandaslargeofadimmingrangeaspossible,atboth115VACand230VAC.Howeversimplificationofthedesignispossibleforbothsingleinputvoltageoperation,nodimmingoroperationwithalimitedrangeof(higherquality)dimmers.

ThisdocumentcontainstheLEDdriverspecification,schematic,PCBdiagram,billofmaterials,transformerdocumentationandtypicalperformancecharacteristics.


图4.TRIAC调光14WLED驱动器参考设计外形图

参考设计电源指标:


图5.TRIAC调光14WLED驱动器参考设计电路图

参考设计材料清单(BOM):



图6.变压器电连接图
详情请见:
http://www.powerint.com/sites/default/files/product-docs/linkswitch-ph_family_datasheet.pdf
和
http://www.powerint.com/sites/default/files/PDFFiles/rdr194.pdf

NXP公司的PCA9626是I2C总线控制的24位LED驱动器,每个LED输出有它本身的8位分辨率的固定频率PWM控制器,工作频率97kHz,占空比从0%到99.6%可调整,使LED能设定到所需亮度.PCA9626工作电压从2.3V到5.5V,100mA漏极开路输出使电压高达40V,内部25MHz振荡器不需要外接元件.本文介绍了PCA9626的主要特性,方框图以及典型应用.

PCA9626

24-bitFm+I2C-bus100mA40VLEDdriver

ThePCA9626isanI2C-buscontrolled24-bitLEDdriveroptimizedforvoltageswitchdimmingandblinking100mARed/Green/Blue/Amber(RGBA)LEDs.EachLEDoutputhasitsown8-bitresolution(256steps)fixedfrequencyindividualPWMcontrollerthatoperatesat97kHzwithadutycyclethatisadjustablefrom0%to99.6%toallowtheLEDtobesettoaspecificbrightnessvalue.Anadditional8-bitresolution(256steps)groupPWMcontrollerhasbothafixedfrequencyof190Hzandanadjustablefrequencybetween24Hztoonceevery10.73secondswithadutycyclethatisadjustablefrom0%to99.6%thatisusedtoeitherdimorblinkallLEDswiththesamevalue.

EachLEDoutputcanbeoff,on(noPWMcontrol),setatitsindividualPWMcontrollervalueoratbothindividualandgroupPWMcontrollervalues.ThePCA9626operateswithasupplyvoltagerangeof2.3Vto5.5Vandthe100mAopen-drainoutputsallowvoltagesupto40V.

ThePCA9626isoneofthefirstLEDcontrollerdevicesinanewFast-modePlus(Fm+)family.Fm+devicesofferhigherfrequency(upto1MHz)andmoredensELypopulatedbusoperation(upto4000pF).

TheactiveLOWOutputEnableinputpin(OE)blinksalltheLEDoutputsandcanbeusedtoexternallyPWMtheoutputs,whichisusefulwhenmultipledevicesneedtobedimmedorblinkedtogetherwithoutusingsoftwarecontrol.

SoftwareprogrammableLEDGroupandthreeSubCallI2C-busaddressesallowallordefinedgroupsofPCA9626devicestorespondtoacommonI2C-busaddress,allowingforexample,allredLEDstobeturnedonoroffatthesametimeormarqueechasingeffect,thusminimizingI2C-buscommands.Sevenhardwareaddresspinsallowupto126devicesonthesamebus.

TheSoftwareReset(SWRST)CallallowsthemastertoperformaresetofthePCA9626throughtheI2C-bus,identicaltothePower-OnReset(POR)thatinitializestheregisterstotheirdefaultstatecausingtheoutputNANDFETstobeOFF(LEDoff).Thisallowsaneasyandquickwaytoreconfigurealldeviceregisterstothesamecondition.

InadditiontothesefeaturesfoundinPCA9633,PCA9634,PCA9635,PCA9622andPCA9624,anewfeaturetocontrolLEDoutputpatternisincorporatedinthePCA9626.Anewcontrolbytecalled‘ChaseByte’allowsenablingordisablingofselectiveLEDoutputsdependingonthevalueoftheChaseByte.ThisfeaturegreatlyreducesthenumberofbytestobesenttothePCA9626whenrepetitivepatternsneedtobedisplayedasincreatingamarqueechasingeffect.

IfthePCA9626on-chip100mANANDFETsdonotprovideenoughcurrentorvoltagetodrivetheLEDs,thenthePCA9635andthePCA9635withlargercurrentorhighervoltageexternaldriverscanbeused.

PCA9626主要特性:

24LEDdrivers.Eachoutputprogrammableat:

Off

On

ProgrammableLEDbrightness

Programmablegroupdimming/blinkingmixedwithindividualLEDbrightness

1MHzFast-modePluscompatibleI2C-businterfacewith30mAhighdrivecapabilityonSDAoutputfordrivinghighcapacitivebuses

256-step(8-bit)linearprogrammablebrightnessperLEDoutputvaryingfromfullyoff(default)tomaximumbrightnessusinga97kHzPWMsignal

256-stepgroupbrightnesscontrolallowsgeneraldimming(usinga190HzPWMsignal)fromfullyofftomaximumbrightness(default)

256-stepgroupblinkingwithfrequencyprogrammablefrom24Hzto10.73sanddutycyclefrom0%to99.6%

24open-drainoutputscansinkbetween0mAto100mAandaretoleranttoamaximumoffstatevoltageof40V.Noinputfunction.

OutputstatechangeprogrammableontheAcknowledgeortheSTOPCommandtoupdateoutputsbyte-by-byteorallatthesametime(defaultto‘ChangeonSTOP’).

ActiveLOWOutputEnable(OE)inputpinallowsforhardwareblinkinganddimmingoftheLEDs

7hardwareaddresspinsallow126PCA9626devicestobeconnectedtothesameI2C-busandtobeindividuallyprogrammed

4softwareprogrammableI2C-busaddresses(oneLEDGroupCalladdressandthreeLEDSubCalladdresses)allowgroupsofdevicestobeaddressedatthesametimeinanycombination(forexample,oneregisterusedfor‘AllCall’sothatallthePCA9626sontheI2C-buscanbeaddressedatthesametimeandthesecondregisterusedforthreedifferentaddressessothat3ofalldevicesonthebuscanbeaddressedatthesametimeinagroup).SoftwareenableanddisableforI2C-busaddress.

AChaseByteallowsexecutionofpredefinedON/OFFpatternforthe24LEDoutputs

SoftwareResetfeature(SWRSTCall)allowsthedevicetoberesetthroughtheI2C-bus

25MHzinternaloscillatorrequiresnoexternalcomponents

Internalpower-onreset

NoisefilteronSDA/SCLinputs

Noglitchonpower-up

Supportshotinsertion

Lowstandbycurrent

Operatingpowersupplyvoltage(VDD)rangeof2.3Vto5.5V

5.5Vtolerantinputsonnon-LEDpins

40℃to+85℃operation

ESDprotectionexceeds2000VHBMperJESD22-A114,200VMMperJESD22-A115and1000VCDMperJESD22-C101

Latch-uptestingisdonetoJEDECStandardJESD78whichexceeds100mA

Packagesoffered:LQFP48,HVQFN48



图1.PCA9626方框图



图2.PCA9626典型应用

详情请见PDF文档

来源：NXP

    Powerint公司的PKS607YN是PeakSwitch系列器件,能满足高峰值/连续功率比的应用需求.PeakSwitch系列集成了700V功率MOSFET,振荡器,用于起动的高压开关电流源,限流和热关断.此外,还包括自动重起,火线欠压检测和频率抖动等功能.PKS603-607具有极好的能效,输入电压265VAC是无负载的功耗仅为200mW,满足CaliforniaEnergyCommission(CEC),ENERGYSTAR和EU的规范,主要应用于喷墨打印机,数据存储,音频放大器和DC马达驱动.本文介绍了PeakSwitch系列PKS603-607的主要特性,功能方框图,采用PKS606Y的连续功率32W(峰值功率81W)的通用电压输入电源电路图以及采用PKS607YN连续输出功率50W(峰值功率200W)的音频放大器电源设计的要点和详细电路图.

PeakSwitchisdesignedtoaddressapplicationswithhighpeak-to-continuouspowerratiodemands.TheveryhighswitchingfrequencyduringpeakpowerloadsandexcELlentloadtransientresponsereducesystemcostaswellascomponentcountandsize.PeakSwitchincorporatesa700VpowerMOSFET,oscillator,highvoltageswitchedcurrentsourceforstartup,currentlimit,andthermalshutdownontoamonolithicdevice.Inaddition,thesedevicesincorporateauto-restart,lineunder-voltagesenseandfrequencyjittering.AninnovativedesignminimizesaudiofrequencycomponentsinthesimpleON/OFFcontrolschemetopracticallyeliminateaudiblenoisewithstandardvarnishedtransformerconstruction.
PKS603-607主要特性:

EcoSmart–ExtremelyEnergy-Efficient
Standbyoutputpower≥0.6Wfor1Winput(highline)
Sleepmodepower≥2.4Wat3Winput(highline)
No-loadconsumption<200mWat265VACinput
SurpassesCaliforniaEnergyCommission(CEC),ENERGYSTAR,andEUrequirements
PeakSwitchFeaturesReduceSystemCost
Deliverspeakpowerofuptothreetimesmaximumcontinuousoutputpower
277kHzoperationduringpeakpowersignificantlyreducestransformersize
ProgrammablesmartAClinesensingprovideslatchingshutdownduringshortcircuit,overloadandopenloopfaults,andpreventsglitchesduringpowerdownorbrownout
TwoexternalcomponentsresetlatchonACremoval
Adaptiveswitchingcycleon-timeextensionincreaseslowlinepeakoutputpower,minimizingbulkcapacitorsize
Adaptivecurrentlimitreducesoutputoverloadpower
FrequencyjitteringreducesEMIfiltercost
TightI2ftolerancesandnegligibletemperaturevariationofkeyparameterseasedesignandlowercost
Accuratehystereticthermalshutdownwithautomaticrecoveryprovidescompletesystemleveloverloadprotectionandeliminatesneedformanualreset
BetterSystemCost/PerformanceoverRCC&Discrete
SimpleON/OFFcontrol–noloopcompensationneeded
Verylowcomponentcount–higherreliabilityandsinglesideprintedcircuitboard
Highbandwidthprovidesfastturnonwithnoovershootandexcellenttransientloadresponse
Peakcurrentlimitoperationrejectslinefrequencyripple
Built-incurrentlimitandhystereticthermalprotection

PKS603-607应用:

Inkjetprinter

Datastorage,audioamplifier,DCmotordrives



图1.PKS603-607功能方框图



图2.采用PKS606Y的连续功率32W(峰值功率81W)的通用电压输入电源电路图

采用PKS607YN连续输出功率50W(峰值功率200W)的音频放大器电源设计要点

Theuniversalinputpowersupplyhastwomainoutputvoltages,+28Vand-28V,andconsistsoftwoparallelconverters.Eachoutputcandeliver25Wcontinuous,100Wpeak.

EachconverterusesaPeakSwitch(PKS607YN)whichshareacommoninputstage.The12Voutputisratedtoprovideanoutputcurrentof333mA.Durationofpeakpoweroutputisthermallylimited,beingdeterminedbyenvironmentandheat-sinking.

Commonmodechokes,L1andL2alongwithY-capacitorsC3,C4,C23andC24formthecommonmodeEMIfilter.InductorsL3,L4andL5andcapacitorsC5,C10andC2providedifferentialmodeEMIfiltering.

Duringstart-up,switchingisinhibiteduntiltheinputvoltageisabovetheundervoltagethreshold,whichisdeterminedwhenacurrentof>25&#61676;AflowsintotheEN/UVPin,setbyR5,R11andR10,R15.

ThecontrollerinU3(U2)skipsswitchingcyclestoregulatetheoutputvoltagebasedonfeedbacktotheEN/UVpin.Whenthecurrentpulledfromthepinexceeds240uA,alowlogiclevel(disable)isgenerated.Atthebeginningofeachcycle,theEN/UVpinstateissampled,andifhigh,thepowerMOSFETinsideU3(U2)isturnedonforthatcycle(enabled).Audioapplicationsdemandthatthepowersupplyoutputvoltagedroopsduringanoverloadcondition,ratherthanshuttingdowncompletely.Theshutdowninhibitcircuit,drivenby555timerU1,pullscurrentfromtheEN/UVpinevery30mstoensurethecontrollerneverentersoutputauto-restartmode,insteadrelyingontheinternalthermalshutdowntoprovideoverloadprotection.

Twoindependentfeedbackloopsareusedtocontrolthevoltagesonthe±28Voutputs.Thisensuresthatbothoutputsaretightlyregulatedandalsoensuresexcellentcross-regulationbetweenoutputs.

设计要点:

Highcrestfactoroftheaudioloadsallowedsmallerheatsinks.
Draintosourcesnubbers(C14,R13andC19,R18)wereusedtoreduceEMI.
ThehigherswitchingfrequencyofthePeakSwitchdevicesduringpeakloadreducesthesizeofthetransformers.
Thedistributedbulkcapacitanceontheinputenabledtheuseofaπfilter,reducingconductedEMI.
Ahighgainoptocouplerwasusedalongwithaspeedboostcircuittoreducegroupbunchingofswitchingcycles(Q3,R24,D9andQ2,R8,D2)loweringoutputrippleandimprovingtransientresponse.

设计亮点:

Replacesline-transformerbasedpowersuppliesinhomeaudioapplications
Compactandlightweight
FasttransientresponseandhighloopbandwidthallowsforexcellentresultswithClass-Damplifiers
Highpeakpowermatchescrestfactorrequiementsofaudiosignals
Savescostbyeliminatingoverdesign
Shutdowninhibitcircuitallowsoutputtodroopduringextremeoverloads,preventingaudibledropouts
Dualconvertordesignmaintainsexcellentcrossregulationbetweenhighvoltagerails
Auxiliaryoutputeliminatesseparatehouse-keepingpowersupply
HighEfficiency
Efficiencygreaterthan75%atfullload



图3.采用PKS607YN连续输出功率50W(峰值功率200W)的音频放大器电源电路图