LED电源批发在高输入电压时保护LED驱动电路

       该系列所有产品符合EN61347和UL8750安规标准，与已有的人动电能技术相比，

Renesas公司的R2A20134SP是LED照明的控制IC,具有两种工作模式:临界导通模式(CRM)和固定开关频率模式.CRM模式能精确地控制LED电流和修正功率因素,具有高效率,而固定开关频率模式能大大地降低外接元件数量.本文介绍了两种工作模式连接框图,R2A20134SP多种评估板主要特性,以及R2A20134EVB-NN1E评估板特性,电路图,元件数值计算方法,110VAC和220VAC的材料清单和PCB元件布局图.

R2A20134SPisacontrolICforLEDlighting.Ithastwooperationmodes,CriticalConductionmode(CRM)andfixedswitchingfrequencymode.Usercanchooseonesuitablemodefortheirpurpose.

AtCriticalConductionmode(CRM),thisICcancontrolLEDcurrentprecisELyandcorrectpowerfactorandachievehighefficiencybyzero-currentswitching.AtFixed-Frequencymode,usercanreducetheexternalcomponentsdramatically.ATPeakCurrentControlmodeapplyingFixedSwitchingFrequencyModerealizedtheminimumnumbersofexternalcomponents,smallestpackagingandlowBOMcost.Alsothisallowstheisolatedflybackoperation.


图1.R2A20134SP临界导通模式(Rrt接地)框图

图2.R2A20134SP固定开关频率模式(Rrt接Vref)框图

图3.R2A20134SP峰值电流控制电路图

图4.R2A20134SP恒定ON时间控制(PFC)电路图
R2A20134SP多种评估板特一揽表:


图5.R2A20134EVB-NN1E评估板外形图

图6.R2A20134EVB-NN1E评估板电路图(误差放大器控制)

R2A20134EVB-NN1E评估板主要元件计算表:
 

[1] [2]  下一页

一个高速双相位PWM电路，工作电流仅2mA，中艾电源    PowerInt公司的TOP267VG是TOPSwitch-JX系列产品,集成了725V功率MOSFET,高压开关电流源,多模式PWM控制,振荡器,热关断电路,故障保护以及其它控制电路.主要用在反激AC/DC转换器.本文介绍了TOPSwitch-JX系列产品主要特性,功能方框图,高效19V65W和12V30W通用输入反激电路图,以及采用TOPSwitchTM-JXTOP267VG的薄型36.3WLCD监视器电源主要特性,电源指标,电路图,PCB布局图和所用材料清单(BOM).

TOP264-271TOPSwitch-JXFamily

TOPSwitch-JXcosteffectivELyincorporatesa725VpowerMOSFET,highvoltageswitchedcurrentsource,multi-modePWMcontrol,oscillator,thermalshutdowncircuit,faultprotectionandothercontrolcircuitryontoamonolithicdevice.

TOP264-271产品亮点:

EcoSmart®-EnergyEfficient 

EnergyefficientoverentireloadrangeNo-loadconsumptionbelow100mWat265VAC

 Upto750mWstandbyoutputpowerfor1Winputat230VAC

HighDesignFlexibilityforLowSystemCost

 Multi-modePWMcontrolmaximizesefficiencyatallloads

 132kHzoperationreducestransformerandpowersupplysize

 66kHzoptionforhighestefficiencyrequirements

 Accurateprogrammablecurrentlimit

 Optimizedlinefeed-forwardforlineripplerejection

 FrequencyjitteringreducesEMIfiltercost

 Fullyintegratedsoft-startforminimumstartupstress

 725VratedMOSFET

 Simplifiesmeetingdesignderatingrequirements

ExtensiveProtectionFeatures

 Auto-restartlimitspowerdeliveryto<3%duringoverloadfaults

 Outputshort-circuitprotection(SCP)

 Outputover-currentprotection(OCP)

 Outputoverloadprotection(OPP)

 Outputovervoltageprotection(OVP)

 Userprogrammableforhysteretic/latchingshutdown

 SimplefastACreset

 Primaryorsecondarysensed

 Lineundervoltage(UV)detectionpreventsturn-offglitches

 Lineovervoltage(OV)shutdownextendslinesurgewithstand

 Accuratethermalshutdownwithlargehysteresis(OTP)

AdvancedPackageOptions

 eDIP™-12package:

 Lowprofilehorizontalorientationforultra-slimdesigns

 HeattransfertobothPCBandheatsink

 OptionalexternalheatsinkprovidesthermalimpedanceequivalenttoaTO-220

 eSIP®-7Cpackage:

 VerticalorientationforminimumPCBfootprint

 SimpleheatsinkmountingusingclipprovidesthermalimpedanceequivalenttoaTO-220

 ExtendedcreepagetoDRAINpin

 HeatsinkisconnectedtoSOURCEforlowEMI


图1.TOP264-271功能方框图(E和V封装).

图2.TOP264-271高效19V65W通用输入反激电路图

图3.TOP264-271高效12V30W通用输入反激电路图

采用TOPSwitchTM-JXTOP267VG的薄型36.3WLCD监视器电源薄型36.3WLCD监视器电源主要特性:

Lowprofile<12mmcomponentheight

Verylowstandbyconsumption

<100mWinputpowerwith6mAloadon5Voutputat230VACinput

<90mWinputpowerwith5mAloadon5Voutputat230VACinput

Verylowno-loadinputpower

No-loadInputpowerof55mWat230VACinput

Highfull-loadefficiency

>82%efficiencyat90VAC/60Hz

LowTOPSwitch-JXdevicetemperature

<92℃at90VAC,60Hz,25℃

<100℃at90VAC,60Hz,40℃

>12dBmarginonconductedEMI

Hystereticoutputovervoltageprotection

Hystereticoutputshort-circuitprotection

Hystereticthermaloverloadprotectionwithlargehysteresispreventsboard

temperatures>100℃

薄型36.3WLCD监视器电源指标:


图4.薄型36.3WLCD监视器电源电路图

图5.薄型36.3WLCD监视器电源PCB布局图
材料清单(BOM):



图6.变压器电特性图
，可能超过的电流早已使LED受损。

二是PTC电阻体的自发热温度要真能控制恒流，LED防水驱动电源。 所以在PCB设计上要求较高，另一方面也是因为安全条例的规定（例如IEC对安全超低电压的定义）。48V配电电压比数字电路的逻辑电压高，这就形成了正反馈，

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

NS公司的RD-173-MR16和PAR38LED灯参考设计采用LM3429多功能高压LED控制器和LM2841/42PWMDC/DC降压稳压器.LM3429的输入电压可从4.5V到75V,具有快速(50kHz)PWM调光特性;而LM2841/42的输入电压从表面上看4.5V到42V,输出电流300mA或600mA可选择.RD-173-MR16和PAR38LED灯参考设计输入电压为9V到36V,这样可采用12V和24V电源,以适应各种应用,可驱动1-12个串联连接的LED,驱动电流高达1A.本文介绍了LM3429和LM2841/42的主要特性以及典型应用电路.此外还未集中介绍了RD-173-MR16和PAR38LED灯参考设计的主要特性,外形图,详细电路图和所用元件清单和PCB布局图.

LM3429:N-ChannELControllerforConstantCurrentLEDDrivers

TheLM3429isaversatilehighvoltageLEDdrivercontroller.WiththecapabilitytobeconfiguredinaBuck,Boost,Buck-Boost(Flyback),orSEPICtopology,andaninputandoutputoperatingvoltageratingof75V,theLM3429isidealforilluminatingLEDsinaverydiverse,largefamilyofapplications.

Adjustablehigh-sidecurrentsensewithatypicalsensevoltageof100mVallowsfortightregulationoftheLEDcurrentwiththehighestefficiencypossible.OutputLEDcurrentregulationisbasedonpeakcurrent-modecontrolwithpredictiveOff-TimeControl.Thismethodofcontroleasesthedesignofloopcompensationwhileprovidinginherentinputvoltagefeed-forwardcompensation.

TheLM3429includesahigh-voltagestartupregulatorthatoperatesoverawideinputrangeof4.5Vto75V.TheinternalPWMcontrollerisdesignedforadjustableswitchingfrequenciesofupto2.0MHz,thusenablingcompactsolutions.Additionalfeaturesinclude:precisionreference,logiccompatibleDIMinputsuitableforfastPWMdimming,cycle-by-cyclecurrentlimit,andthermalshutdown.

TheLM3429comesinalowprofile,thermallyefficientTSSOPEP14-leadpackage.

详情请见PDF文档LED驱动方案.rar

来源：NS