注:VLED值依不同发光颜色各有不同,用稳压电源驱动LED时,为了控制电流,通常需要串联电阻器.
例:一个额定输出电压为DC24V,功率为10W电源,使用额定正向电流20mA,耗散功率为70mW额定的正向电压为1.8V.可配置多少个LED呢?(取所得数据的整数)
可以带10组支路,每支路14个LED串联构成的电路,共140个LED.
工作原理图
E273.5WLED灯泡驱动方案推介：
方案主芯片:意法半导体(STMicro)型号ALTAIR03TR(SO16贴片封装)
准谐振型工作模式芯片，LED调光电源。
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)***ltiplehostinterfaceoptions,anintegratedLCDdriver,andconfigurableI/Os,itisidealformeteredpowerdistributionunits(PDUs)andrackenclosuresforthedatacenteraswellasintelligentpowerstripsandsubpanelsinthegrid-friendlydigitalhome.
Atthemeasurementinterface,thedevice***esfromthesensorsarefedtoTeridian’spatentedSingleConverterTechnology?whichusesa21-bitdelta-sigmaADC,independent32-bitcomputeengine(CE),digitaltemperaturecompensation,andprecisionvoltagereferencestoprovidebetterthan0.5%accuracyoverawide2000:1dynamicrange.
TheintegratedMPUcoreand128KBofFlashmemoryprovidesaflexiblemeansofconfiguration,post-processing,dataformatting,interfacingtohostprocessorviaaUARTorSPIinterface,displayingoutputdatatoanLCD,***tefirmwareforcommonapplicationsisavailabl***atively,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
The78M6618evaluationboardisadesignexamp***rdincludesone78M6618IC,anAC-DCpowersupply,oneACinput,eightswitchedoutputs(relays),andconnectorstotheserialinterfacesandDIOpins.
图5.78M6618评估板外形图
详情请见:
***/***
，如嵌灯、橱柜灯及台灯等。该标准针对住宅应用部分要求功率因数高于0.7，以创新的主控技术来管理led功耗。
25个组件就足以应对一盏10瓦LED灯所需(效能等同60瓦)，本文介绍了Powerint公司的高功率因数（PF）TRIAC调光LED驱动器。该驱动器设计用以驱动30V（在0.5A的电流下）的额定led串电压，中艾电源LED调光电源
Semtech公司的SX1507,SX1508和SX1509是超低功耗4/8/16路通用并行输入/输出(GPIO)扩展器,并集成了LED驱动器,工作电压1.2V-3.6V,主要用在手机,PDA,MP3播放器,数码相机,笔记本电脑,GPS和其它以电池为能源的设备.本文介绍SX1507,SX1508和SX1509主要特性,方框图,典型应用框图和电路,以及SX1508EVK评估板电路图和PCB布局图.
TheSX1507,SX1508andSX1509arecompleteultralowvoltage1.2Vto3.6VGeneralPurposeparallELInput/Output(GPIO)***milyofGPIOscomesin4-,8-,16-channelconfigurationandallowseasyserialexpansionofI/***vicescanprovideadditionalcontrolandmonitoringwhenthemicrocontrollerorchipsethasinsufficientI/Oports,orinsystemswhereserialcommunicationandcontrolfromaremotelocationisadvantageous.
Thesedevicescanalsoactasalevelshiftertoconnectamicrocontrollerrunningatonevoltageleveltoacomponentrunningatadifferentvoltagelevel,***eisoperatingaslowas1.425VwhilethedualI/Obankscanoperatebetween1.2Vand3.6Vindependentofthecorevoltageandeachother(5.5Vtolerant).
TheSX1507,SX1508andSX1509featureafullyprogrammableledDriverwithinternaloscillatorforenhancedlightingcontrolsuchasintensity(via256-stepPWM),blinkingandbreathing(fadein/out)***tion,keypadapplicationisalsosupportedwiththeon-chipscanningenginewhichenablescontinuouskeypadmonitoringupto64keyswithoutanyadditionalhostinteractionandfurtherreducethebusactivity.
TheSX1507,SX1508andSX1509havetheabilitytogeneratemask-programmableinterruptsbasedonfalling/***atedpinindicatestoahostcontrollerthatastatechangeoccurredinoneormoreofthelines.
EachGPIOisprogrammablevia8-bitconfigurationregisterssuchasdataregisters,directionregisters,pull-up/pull-downregisters,***℃to+85℃temperaturerange.
SX105x主要特性:
1.2Vto3.6VLowOperatingVoltagewithDualIndependentI/ORails(VCC1,VCC2)
EnableDirectLevelShiftingBetweenI/OBanksandHostController
5.5VTolerantI/Os,Upto15mAOutputSinkonAllI/Os(NoTotalSinkCurrentLimit)
IntegratedLEDDriverforEnhancedLighting
IntensityControl(256-stepPWM)
BlinkControl(224On/Offvalues)
BreathingControl(224FadeIn/Outvalues)
On-ChipKeypadScanningEngine
SupportUpto8x8Matrix(64Keys)
ConfigurableInputDebouncer
4/8/16ChannelsofTrueBi-directionalStyleI/O
ProgrammablePull-up/Pull-down
Push/PullorOpen-drainoutputs
ProgrammablePolarity
OpenDrainActiveLowInterruptOutput(NINT)
BitMaskable
ProgrammableEdgeSensitivity
Built-inClockManagement(Internal2MHzOscillator/ExternalClockInput,7clockvalues)
OSCIOcanbeConfiguredasGPO
400kHzI2CCompatibleSlaveInterface
4User-SelectableI2CSlaveAddresses
Power-OnResetandResetInput(NRESET)
UltraLowCurrentConsumptionoftyp.1uA
-40℃to+85℃OperatingTemperatureRange
2kVHBMESDProtection
SmallFootprintPackages
Pb&HalogenFree,RoHS/WEEEcompliant
SX105x应用:
Cellphones,PDAs,MP3players
Digitalcamera,Notebooks,GPSUnits
Anybatterypoweredequipment
图1.4路SX1507方框图
图2.8路SX1508方框图
图3.16路SX1508方框图
图4.8路SX1508典型应用电路
图5.8路SX1508典型应用框图
图***1508EVK评估板外形图
图***1508EVK评估板电路图
图***1508EVK评估板布局图
详情请见:
***/datasheet/sx150x_***
和
***/datasheet/sx1508evk_users_***
，以用于展示整个解决方案，因此可简化EMI滤波设计。这种拓扑结构通常需要在初级侧使用一个箝位电路。不过，
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)***ltiplehostinterfaceoptions,anintegratedLCDdriver,andconfigurableI/Os,itisidealformeteredpowerdistributionunits(PDUs)andrackenclosuresforthedatacenteraswellasintelligentpowerstripsandsubpanelsinthegrid-friendlydigitalhome.
Atthemeasurementinterface,thedevice***esfromthesensorsarefedtoTeridian’spatentedSingleConverterTechnology?whichusesa21-bitdelta-sigmaADC,independent32-bitcomputeengine(CE),digitaltemperaturecompensation,andprecisionvoltagereferencestoprovidebetterthan0.5%accuracyoverawide2000:1dynamicrange.
TheintegratedMPUcoreand128KBofFlashmemoryprovidesaflexiblemeansofconfiguration,post-processing,dataformatting,interfacingtohostprocessorviaaUARTorSPIinterface,displayingoutputdatatoanLCD,***tefirmwareforcommonapplicationsisavailabl***atively,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
The78M6618evaluationboardisadesignexamp***rdincludesone78M6618IC,anAC-DCpowersupply,oneACinput,eightswitchedoutputs(relays),andconnectorstotheserialinterfacesandDIOpins.
图5.78M6618评估板外形图
详情请见:
***/***
，只有约10%的效率，有助于将额定输出电压和恒流调节阈值严格控制在中心位置。
3、RF1充当保险丝：确保其额定值能够在电源首次与AC连接时耐受瞬态耗散。使用绕线式电阻或超大号电阻。
4、假负载电阻R4在故障条件下（如负载断开）维持输出电压。出过压保护。
，Linear公司的LT3760是集成了升压DC/DC控制器的8路LED驱动器,能驱动高达45V的led.输入电压从6V到40V,40mA时的LED匹配电流为±2%,典型值为±0.7%,调光比高达3000:1,可编程的频率从100kHz到1MHz,主要用于汽车,笔记本低电脑和TV监视器的背光.本文介绍LT3760主要特性,方框图,36W,28W,15W,29W,25W以及14WLED驱动器应用电路.
TheLTR3760isan8-channELLEDdriverwithastep-upDC/DCcontrollercapableofdrivingupto45VofLEDs.
Eachchannelcontainsanaccuratecurrentsinkwith±2%***lsfollowamasterpr***voltageadaptstovariationsinLEDVFforoptimumefficiencyandopenLEDfaultsdonotaffecttheoperationofconnectedLEDstrings.
TheLT3760allowsaPWMdimmingrangeupto3000:1andananalogdimmingrangeupto25:***ingfrequencycanbeprogrammedfrom100kHzupto1MHzusingasingleresistororsynchronizedtoanexternalclock.
Additionalfeaturesinclude:programmablemaximumVOUTforopenLEDprotection,afaultflagforopenLED,programmableLEDcurrentderatingvstemperature,***3760isavailableinathermallyenhanced28-pinTSSOPPackage.
LT3760主要特性:
Upto45VofLEDsx100mA,8-ChannelLEDDriver
WideInputRange:6Vto40V
±2%LEDCurrentMatchingat40mA(Typ±0.7%)
Upto3000:1TrueColorPWM™DimmingRange
SingleResistorSetsLEDCurrent(20mAto100mA)
LEDCurrentRegulatedEvenforPVIN>VOUT
OutputAdaptstoLEDVFforOptimumEfficiency
FaultFlag+ProtectionforOpenLEDStrings
ProtectionforLEDPintoVOUTShort
ParallelChannelsforHigherLEDCurrent
ProgrammableLEDCurrentDeratingvsTemperature
AccurateUndervoltageLockoutThresholdwithProgrammableHysteresis
ProgrammableFrequency(100kHzto1MHz)
SynchronizabletoanExternalClock
LT3760应用:
Automotive,NotebookandTVMonitorBacklight
图***3760方框图
图2.效率92%36W背光LED驱动器
图3.效率92%36WLED驱动器:1MHz升压,8串LED,每串100mA
图4.效率92%28WLED驱动器:750kHz升压,8串LED,每串80mA
图5.15WLED驱动器:750kHz升压,8串LED,每串55mA
图6.29WLED驱动器:400kHz升压,2串LED,每串350mA
图7.25WLED驱动器:400kHz升压,3串LED,每串200mA
图8.28WLED驱动器:700kHz升压,4串LED,每串160mA
图9.14WLED驱动器:700kHz升压,4串LED,每串80mA
图10.28WLED驱动器:1MHzSPEIC,8串LED,每串100mA
，微控制器必须与在不同的电源电压运作外围设备进行通信。这种设计思路，。