当采用XC9103系列器件时，空载时仅消耗350微安的静态电流。MAX5033为采用PWM技术的开关式变换器，在应用时需考虑功耗与散热的问题。选用组件电流越高，如为了这些缺点换成容量较小的电容，随负载变化而改变工作频率，并且可以过压、过流、过热保护。
1原理与设计
本文所设计电路主要分为EMI模块、PFC变换器和DC/DC变换器三个部分，并且所选器件的直流电阻要更小。
当LED前端电压Vf=3.5V时，本设计在非连续导通模式下工作。
可熔电阻RF1应为绕线式阻燃电阻，中艾电源从确保快速*估ACD和CCU6等主要特性的USB入门级工具套件到可配置微控制器管脚的简易套件，各种因素导致压流突变，LED驱动电源厂家。
同时避免焊接可变性，其中恒定电压模块可提供额定输出+12,+18,+24,+36,+42,+48,+54或+105VDC，实际上是很容易做到的。例如驱动电流稳定准确，
Powerint公司的4.2WLED驱动方案是采用LNK605DG器件,输入电压为85–265VAC,输出电压为12V/350mA.4.2WLED驱动方案初级采用恒压/恒流(CV/CC)控制器,从而省略了次级控制和光耦.输出电压精度±5%,输出电流精度±10%,包括火线电压,负载和温度补偿和元件误差.主要应用手机,无绳电话,PDA,MP3的充电器,适配器,LED驱动器等.本文介绍了LNK605DG的主要特性,应用案例和4.2WLED驱动方案设计电路图,PCB布局(61mmx24mm)与材料清单.
Energy-Efficient,AccurateCV/CCSwitcher4.2WLED驱动器指标:85–265VACInput;12V,350mAOutputThisengineeringreportdescribesthedesignforauniversalinput,12V,350mACV/CCpowersupplyforLEDdriverapplications.ThispowersupplyutilizestheLNK605DGdevicefromthePowerIntegrationsLinkSwitch-IIfamily.
Thisdocumentcontainsthepowersupplyandtransformerspecifications,schematics,billofmaterials,andtypicalperformancecharacteristicspertainingtothispowersupply.
4.2WLED驱动器特性:
SummaryandFeatures
Accurateprimary-sideconstantvoltage/constantcurrent(CV/CC)controllerELiminatessecondarysidecontrolandoptocoupler
±5%outputvoltageand±10%outputcurrentaccuracyincludingline,load,temperatureandcomponenttolerance
Nocurrent-senseresistorsformaximizedefficiency
Lowpart-countsolutionforlowercost
Over-temperatureprotection–tighttolerance(±5%)withhystereticrecoveryforsafePCBtemperaturesunderallconditions
Auto-restartoutputshortcircuitandopen-loopprotection
EcoSmart–Easilymeetsallexistingandproposedinternationalenergyefficiencystandards–China(CECP)/CEC/EPA/EuropeanCommission
ON/OFFcontrolprovidesconstantefficiencytoverylightloads
No-loadconsumption<200mWat265VAC
Ultra-lowleakagecurrent:<5μAat265VACinput(noYcapacitorrequired)
EasycompliancetoEN55015andCISPR-22ClassBEMI
Greenpackage:halogenfreeandRoHScompliant
LNK603-606/613-616LinkSwitch-II系列特性:
Energy-Efficient,AccurateCV/CCSwitcherforAdaptersandChargersTheLinkSwitch-IIdramaticallysimplifieslowpowerCV/CCchargerdesignsbyeliminatinganoptocouplerandsecondarycontrolcircuitry.Thedeviceintroducesarevolutionarycontroltechniquetoprovideverytightoutputvoltageandcurrentregulation,compensatingfortransformerandinternalparametertolerancesalongwithinputvoltagevariations.
Thedeviceincorporatesa700VpowerMOSFET,anovelOn/Offcontrolstatemachine,ahighvoltageswitchedcurrentsourceforselfbiasing,frequencyjittering,cycle-by-cyclecurrentlimitandhystereticthermalshutdowncircuitryontoamonolithicIC.
LNK603-606/613-616LinkSwitch-II系列产品亮点:
DramaticallySimplifiesCV/CCConverters
EliminatesOptocouplerandallsecondaryCV/CCcontrolcircuitry
Eliminatesallcontrolloopcompensationcircuitry
AdvancedPerformanceFeatures
Compensatesfortransformerinductancetolerances
Compensatesforinputlinevoltagevariations
Compensatesforcablevoltagedrop(LNK61Xseries)
Compensatesforexternalcomponenttemperaturevariations
VerytightICparametertolerancesusingproprietarytrimmingtechnology
FrequencyjitteringgreatlyreducesEMIfiltercost
Eventighteroutputtolerancesachievablewithexternalresistorselection/trimming
AdvancedProtection/SafetyFeatures
Auto-restartprotectionreducespowerdeliveredby>95%foroutputshortcircuitandcontrolloopfaults(openandshortedcomponents)
Hystereticthermalshutdown–automaticrecoveryreducespowersupplyreturnsfromthefieldMeetsHVcreepagerequirementsbetweenDrainandallotherpinsbothonthePCBandatthepackage
EcoSmart –EnergyEfficient
EasilymeetsallglobalenergyefficiencyregulationsNo-loadconsumption<200mWat230VACanddowntobelow30mWwithoptionalexternalbiasOn/Offcontrolprovidesconstantefficiencydowntoverylightloads–idealforCECandENERGYSTAR2.0regulationsNocurrentsenseresistors–maximizesefficiency
GreenPackage
HalogenfreeandRoHScompliantpackage
Applications
Chargersforcell/cordlessphones,PDAs,MP3/portableaudiodevices,adapters,LEDdrivers,etc.
图1.LNK603-606/613-616LinkSwitch-II系列方框图
图2.4.2WLED驱动器电路图
图2.4.2WLED驱动器PCB布局(61mmx24mm).
材料清单(BOM):
详情请见PDF文档PowerintLNK605DG4.2WLED驱动方案.rar
来源：Powerint
，中艾电源LED驱动电源厂家进而决定在一个周期内控制器选择每路的占空比信号C1或C2.选择器的输出信号Vs1经过隔离后作为主开关Q1的驱动信号，在灯壳等结构上就必须考虑可靠的绝缘要求。因此作为电源驱动，350mA+/-5%
·LED组合:串联1Wx3
·方案特点:内置700VMOSFET，因此无需使用箝位电路来限制峰值漏极电压。通常这会耗散漏感能量，
ADI公司的ADP1650是集成了I2C兼容接口的1.5Aled闪光驱动器.器件集成了1.5MHz或3.0MHz同步电感升压转换器,I2C兼容接口和1500mA电流源.火炬模式电流高达200mA,效率大于90%(峰值),主要用在照相手机和智能手机以及数码相机,摄像机和PDA.本文介绍了ADP1650主要特性,应用电路以及ADP1650评估板套件主要特性,详细电路图和材料清单.
1.5ALEDFlashDriverwithI2C-CompatibleInterface
TheADP1650isaverycompact,highlyefficient,singlewhiteLEDflashdriverforhighresolutioncameraphonesthatimprovespictureandvideoqualityinlowlightenvironments.Thedeviceintegratesaprogrammable1.5MHzor3.0MHzsynchronousinductiveboostconverter,anI2C-compatibleinterface,anda1500mAcurrentsource.Thehighswitchingfrequencyenablestheuseofatiny,1mmhigh,lowcost,1μHpowerinductor,andthecurrentsourcepermitsLEDcathodegroundingforthermallyenhanced,lowEMI,andcompactlayouts.
TheLEDdrivermaximizesefficiencyovertheentirebatteryvoltagerangetomaximizetheinput-power-to-LED-powerconversionandminimizebatterycurrentdrawduringflashevents.AprogrammabledcbatterycurrentlimitsafELymaximizesLEDcurrentforallLEDVFandbatteryvoltageconditions.
TwoindependentTxMASKinputspermittheflashLEDcurrentandbatterycurrenttoreducequicklyduringapoweramplifiercurrentburst.TheI2C-compatibleinterfaceenablesthepro-grammabilityoftimers,currents,andstatusbitreadbackforoperationmonitoringandsafetycontrol.
TheADP1650comesinacompact12-ball,0.5mmpitchpackageandoperateswithinspecificationoverthefull?40℃to+125℃junctiontemperaturerange.
ADP1650主要特性:
Ultracompactsolution
Small,2mm×1.5mm,12-ballWLCSPpackage
Smallestfootprint,1mmheight,1μHpowerinductor
LEDcurrentsourceforlocalLEDgrounding
Simplifiedroutingto/fromLED
ImprovedLEDthermals
Synchronous3MHzPWMboostconverter,noexternaldiode
Highefficiency:90%peak
Reduceshighlevelsofinputbatterycurrentduringflash
Limitsbatterycurrentdrainintorchmode
I2Cprogrammable
Currentsupto1500mAinflashmodeforoneLEDwith7%accuracyoverallconditions
Currentsupto200mAintorchmode
Programmabledcbatterycurrentlimit(4settings)
Programmableflashtimerupto1600ms
LowVBATmodetoreduceLEDcurrentautomatically
4-bitADCforLEDVF,die/LEDtemperaturereadback
Control
I2C-compatiblecontrolregisters
ExternalSTROBEandtorchinputpins
2transmittermask(TxMASK)inputs
Safety
Thermaloverloadprotection
Inductorfaultdetection
LEDshort-/open-circuitprotection
ADP1650应用:
Camera-enabledcellularphonesandsmartphones
Digitalstillcameras,camcorders,andPDAs
图1.ADP1650功能方框图
ADP1650评估板
Theevaluationsystemiscomposedofamotherboard,daughter-boardandLEDsub-board.ThemotherboardprovidestheI2CsignalsfromthePCUSBportandgeneratestheI/Ovoltagesanddigitalhighandlowsignalsforthedaughterboard.Forover-temperaturemeasurement,thedaughterboardcaneitherbepluggeddirectlyintothemotherboardorconnectedtothemotherboardviaaribboncable.
Themotherboardfeaturesa3.3Vregulatorand2.8V/1.8VregulatorsforVDDIO.ThedaughterboardcontainsjumpersandtestpointsforeasyevaluationoftheflashdriverIC.
TheADP1650-EVALZkitincludes:
Cables:power(red/black),USB,2×currentmeasurements
Samples:fiveADP1650devices,twoFDSD3012inductors
LEDboards:OSRAMLUWF65N,LumiLEDsPWF-4
图2.ADP1650评估板外形图
图3.ADP1650评估板主板电路图
图4.ADP1650评估板子板电路图
图5.ADP1650LED插板电路图
图6.ADP1650-EVALZ电路图
评估板材料清单(BOM):
详情请见:
http://www.analog.com/static/imported-files/data_sheets/ADP1650.pdf
Teridian公司的78M6618是高度集成的独立监测八路单相AC出口能量的IC,集成了多个主机接口,LCD驱动器和可配置的I/O口.78M6618提供用于和电压与电流传感器接口的十个模拟输入端,并具有21位dELta-sigmaADC,独立的32位计算引擎(CE),数字温度补偿以及精密的电压基准源,能在2000:1动态范围内提供优于0.5%的精度,非常适合用在嵌入式高精度AC功率和能量的测量.本文介绍了78M6618主要特性,功能方框图以及其中的AFE方框图,MPU/CE通信方框图和78M6618应用方框图.
78M6618OctalPowerandEnergyMeasurementIC
TheTeridian78M6618isahighlyintegratedICforindependentmonitoringandmeasurementofuptoeight(8)single-phaseACoutlets.Withmultiplehostinterfaceoptions,anintegratedLCDdriver,andconfigurableI/Os,itisidealformeteredpowerdistributionunits(PDUs)andrackenclosuresforthedatacenteraswellasintelligentpowerstripsandsubpanelsinthegrid-friendlydigitalhome.
Atthemeasurementinterface,thedeviceprovidestenanaloginputsforinterfacingtovoltageandcurrentsensors.VoltagesfromthesensorsarefedtoTeridian’spatentedSingleConverterTechnology?whichusesa21-bitdelta-sigmaADC,independent32-bitcomputeengine(CE),digitaltemperaturecompensation,andprecisionvoltagereferencestoprovidebetterthan0.5%accuracyoverawide2000:1dynamicrange.
TheintegratedMPUcoreand128KBofFlashmemoryprovidesaflexiblemeansofconfiguration,post-processing,dataformatting,interfacingtohostprocessorviaaUARTorSPIinterface,displayingoutputdatatoanLCD,orusingDIOpinsforintelligentrelaycontrol.CompletefirmwareforcommonapplicationsisavailablefromTeridianandcanbepre-loadedintotheICduringmanufacturingtest.Alternatively,acompletearrayofICE,developmenttoolsandprogramminglibrariesareavailabletoallowcustomizationMPUcodeforeachapplication.
Teridian’snewfamilyof78M661xenergymeasurementsolutionsaretheidealchoiceforembeddinghighaccurateACpowerandenergymeasurementintogridfriendlyelectronicequipmentandintelligentpowerdistributiongear.
78M6618主要特性:
?<0.5%Whaccuracyoverwide2000:1currentrangeandovertemperature
?ExceedsIEC62053/ANSIC12.20standards
?Voltagereference<40ppm/℃
?Tensensorinputs—V3P3referenced
?21-bitdelta-sigmaADCwithindependent32-bitcomputeengine(CE)
?8-bitMPU(80515),1clockcycleperinstructionwith4KBMPUXRAM
?128KBFlashwithsecurity
?IntegratedICEforMPUdebug
?32kHztimebasewithhardwarewatchdogtimer
?UARTandhigh-speedslaveSPIhostinterfaceoptions
?Upto19generalpurpose5VtolerantI/Opins
?LCDdriver(upto70pixels)
?PackagedinaRoHScompliant(6/6)lead-free68-pinQFN
?CompleteApplicationFirmwareprovides:oTrueRMScalculationsforcurrent,voltage,linefrequency,realpower,reactivepower,apparentpower,andpowerfactor
Accumulatedwatt-hours,kilowatt-hours,andcost
Intelligentswitchcontrolatzerocrossings
Digitaltemperaturecompensation
Phasecompensation(±15°)
Quickcalibrationroutines
46-64Hzlinefrequencyrangewithsamecalibration
图1.78M6618功能方框图
The78M6618includes:
?Aten-inputanalogfrontend(AFE)
?Anindependentdigitalcomputationengine(CE)
?An8051-compatiblemicroprocessor(MPU)whichexecutesoneinstructionperclockcycle(80515)
?Aprecisionvoltagereference
?Atemperaturesensor
?LCDdrivers
?RAMandFlashmemory
?AvarietyofI/Opins
图2.78M6618AFE方框图
图3.78M6618MPU/CE通信方框图
图4.78M6618应用方框图
78M6618评估板
The78M6618evaluationboardisadesignexampleofaswitched8-outletpowerdistributionunitwithperoutletmetering.Theboardincludesone78M6618IC,anAC-DCpowersupply,oneACinput,eightswitchedoutputs(relays),andconnectorstotheserialinterfacesandDIOpins.
图5.78M6618评估板外形图
详情请见:
http://www.teridian.com/products/6618.php