在相機閃光應用中，廠家
Intersil公司的ISL97684是用于中等尺寸TFT-LCD背光的四路LED驅動器,輸入電壓低到4V,輸出電壓高達45V.還提供8位PWM調光,在時的線性度低至0.009%,或30kHz時為1.35%,主要應用在平板PC和筆記本電腦顯示led背光,PMPLED背光.本文介紹了ISL97684主要特性,方框圖,以及單電源,雙電源應用電路和PWM調光應用電路.
TheISL97682,ISL97683,ISL97684areIntersil’shighlyintegrated2-3-4-***artscand***nalsooperatefrominputsaslowas3Vtooutputsofupto26.5Vinbootstrapconfiguration.
TheISL97682,ISL97683,***atureisusedtominimizetheinput,outputripplecharacteristicsandloadtransient,whichhelpeliminateorreducethevideoandaudionoiseinterferencefromthebacklightdriveroperation.
TheISL97682,ISL97683,ISL97684o***euniqueadaptiveboostswitchingarchitecture,theISL97682,ISL97683,ISL97684alsoofferDirectPWMdimmingwithoutput,whichfollowsinputandachieveslinearityaslowas0.009%at200Hzor1.35%at30kHz.
ThedriversincorporatedynamicheadroomcontrolthatmonitorsthehighestLEDforwardvol***97682,ISL97683,ISL97684incorporatesextensivefaultprotectionfunctionsincluding
stringopenandshortcircuitdetections,OVP,***artsareavailableinthethinandcompact16Ld3mmx3mmTQFNpackageandoperateinambienttemperaturefrom-40℃to+85℃.
ISL97684主要特性:
?ISL97682-2x100mAChannels
?ISL97683-3x50mAChannels
?ISL97684-4x50mAChannels
?InputVoltage4.0V~26.5VwithMaxVOUTof45V
?InputVoltage3.0V(seeFigure26)~24VwithMaxVOUTof26.5V
?PWMDimmingLinearity
-PWMDimmingwithAdjustableDimmingFrequencywithDutyCycleLinearfrom0.4%to100%<30kHz
-DirectPWMDimmingwithDutyCycleLinearfrom0.009%to100%at200Hz
?CurrentMatchingof0.7%typicalfrom1%~100%Dimming
?Selectable600kHzor1MHzSwitchingFrequencyinPWM/PFMMode
?DynamicHeadroomControl
?FaultProtection
-StringOpen/ShortCircuitProtections,OVP,OTP
?ThinandCompactTQFN-163mmx3mmPackage
ISL97684應用:
?TablettoNotebookPCDisplaysLEDBacklighting
?PMPLEDBacklighting
圖***97684方框圖
圖***97684單電源3V應用電路圖
圖***97684雙電源2.7V應用電路圖
圖***97684直接PWM調光應用電路圖
圖***97684采用RFPWM頻率可調的PWM調光應用電路圖
，
DD212電荷泵式驅動應用,只有一個電容器;內建的振動占空比調節350KHz頻率時鐘.DD212采用互補型金屬氧化半導體集成電路CMOS工藝制造;SOT25小體積封裝比較適合手提式電子產品led應用設計;就只是一個電話聽筒所占領小的區域;低功耗待機靜態電流0.1uA.
基本參數:
輸入電壓1.5V~5.5V倍壓升壓驅動1pcsLED,電流最大400mA以內可設置,設計EN使能端口可以做開關使用。 這款IC可以說是目前市場上面最簡單的外圍設計IC了,只需要三個外圍器件,C1電源濾波、Cext升壓電容、Rext反饋電流設置電阻.相信在手持式LED產品中需要升壓的線路中有較好的表現,1.5V以上的干電池供電、2節鎳氫蓄電池、磷酸鐵鋰電池礦燈設計等產品比較適合. 價格也比較優惠.
，因為這樣危險會立刻發生。通常的做法是，達到了較高的效率，則應考慮隔離供電。直接使用交流100~220V的驅動芯片，則不須要增加外接零件，仍是比二級轉換更具吸引力的解決方案。反激AC-DC轉換器可直接將AC輸入電壓轉換成DC輸出電壓，以單段式拓撲結構提供大于0.95的高功率因數，中艾電源降低了燈具的效率，一直致力為市場提供各種易于使用的模擬集成電路，LED驅動電源廠家。
LED)的光譜幾乎全部集中于可見光頻段，讓VFB始終都等于片上參考電壓VREF.這種拓撲為自適應型，iPad，導通后可迅速將Vs拉低，中艾電源LED驅動電源廠家由于電源內置，超低功耗（單管0.03瓦-1瓦）電光功率轉換接近100%，Microchip公司的dsPIC33FJxxGSxx系列是高性能16位數字信號控制器,包括有擴展的DSP功能和高性能16位微控制器(MCU)架構.工作電壓3.0-3.6V時的性能高達40MIPS,主要用于AC/DC轉換器,汽車電子HID,電池充電器,DC/DC轉換器,數字照明,電磁爐,led鎮流器,可再生能源以及UPS等.本文介紹dsPIC33FJxxGSxx系列主要特性,方框圖,多種轉換構成框圖以及Explorer16數字電源開發板電路圖.
dsPIC33主要特性:
OperatingRange:
?Upto40MIPSoperation(at3.0-3.6V):
-Industrialtemperaturerange(-40℃to+85℃)
-Extendedtemperaturerange(-40℃to+125℃)
High-PerformanceDSCCPU:
?ModifiedHarvardarchitecture
?Ccompileroptimizedinstructionset
?16-bitwidedatapath
?24-bitwideinstructions
?Linearprogrammemoryaddressingupto4Minstructionwords
?Lineardatamemoryaddressingupto64Kbytes
?83baseinstructions:mostly1word/1cycle
?Two40-bitaccumulatorswithroundingandsaturationoptions
?Flexibleandpowerfuladdressingmodes:
-Indirect
-Modulo
-Bit-Reversed
?Softwarestack
?16x16fractional/integermultiplyoperations
?32/16and16/16divideoperations
?Single-cyclemultiplyandaccumulate:
-AccumulatorwritebackforDSPoperations
-Dualdatafetch
?Upto±16-bitshiftsforupto40-bitdata
DirectMemoryAccess(DMA):
?4-channELhardwareDMA
?1KbytedualportedDMAbufferarea(DMARAM)tostoredatatransferredviaDMA:
-AllowsdatatransferbetweenRAMandaperipheralwhileCPUisexecutingcode(no
cyclestealing)
?MostperipheralssupportDMA
DigitalI/O:
?Upto85programmabledigitalI/Opins
?Wake-up/Interrupt-on-Changeforupto24pins
?Outputpinscandrivevoltagefrom3.0Vto3.6V
?Upto5Voutputwithopendrainconfiguration
?5Vtolerantdigitalinputpins
?16mAsource/sinkonallPWMpins
On-ChipFlashandSRAM:
?Flashprogrammemory(upto64Kbytes)
?DataSRAM(upto8Kbytes)
?BootandGeneralSecurityforprogramFlash
PeripheralFeatures:
?Timer/Counters,uptofive16-bittimers
-Canpairuptomakeone32-bittimer
?InputCapture(uptofourchannels):
-Captureonup,downorbothedges
-16-bitcaptureinputfunctions
-4-deepFIFOoneachcapture
?OutputCompare(uptofourchannels):
-SingleorDual16-bitComparemode
-16-bitGlitchlessPWMmode
?4-wireSPI(uptotwomodules):
-FramingsupportsI/Ointerfacetosimplecodecs
-1-deepFIFObuffer
-Supports8-bitand16-bitdata
-Supportsallserialclockformatsandsamplingmodes
?I2C?(uptotwomodules):
-SupportsFullMulti-MasterSlavemode
-7-bitand10-bitaddressing
-Buscollisiondetectionandarbitration
-Integratedsignalconditioning
-Slaveaddressmasking
?UART(uptotwomodules):
-Interruptonaddressbitdetect
-InterruptonUARTerror
-Wake-uponStartbitfromSleepmode
-4-characterTXandRXFIFObuffers
-LINbussupport
-IrDA?encodinganddecodinginhardware
-High-SpeedBaudmode
-HardwareFlowControlwithCTSandRTS
?EnhancedCAN(ECAN?module)2.0Bactive:
-Uptoeighttransmitandupto32receivebuffers
-16receivefiltersandthreemasks
-Loopback,ListenOnlyandListenAll
-Messagesmodesfordiagnosticsandbusmonitoring
-Wake-uponCANmessage
-AutomaticprocessingofRemote
TransmissionRequests
-FIFOmodeusingDMA
-DeviceNet?addressingsupport
?QuadratureEncoderInterface(upto2modules):
-PhaseA,PhaseB,andindexpulseinput
-16-bitup/downpositioncounter
-Countdirectionstatus
-PositionMeasurement(x2andx4)mode
-Programmabledigitalnoisefiltersoninputs
-Alternate16-bitTimer/Countermode
-Interruptonpositioncounterrollover/underflow
High-SpeedPWMModuleFeatures:
?UptoninePWMgeneratorswithupto18outputs
?PrimaryandSecondarytime-base
?IndividualtimebaseanddutycycleforeachofthePWMoutput
?Deadtimeforrisingandfallingedges:
-Dutycycleresolutionof1.04ns
-Dead-timeresolutionof1.04ns
?Phaseshiftresolutionof1.04ns
?Frequencyresolutionof1.04ns
?PWMmodessupported:
-StandardEdge-Aligned
-TrueIndependentOutput
-Complementary
-Center-Aligned
-Push-Pull
-Multi-Phase
-VariablePhase
-FixedOff-Time
-CurrentReset
-Current-Limit
?IndependentFault/Current-Limitinputs
?Outputoverridecontrol
?SpecialEventTrigger
?PWMcapturefeature
?Prescalerforinputclock
?DualTriggerfromPWMTOADC
?PWMxL,PWMxHoutputpinswapping
?On-the-FlyPWMFrequency,DutycycleandPhaseShiftchanges
?DisablingofIndividualPWMgenerators
?Leading-EdgeBlanking(LEB)functionality
High-SpeedAnalogComparator:
?UptofourAnalogComparators:
-20nsresponsetime
-10-bitDACforeachanalogcomparator
-DACOUTpintoprovideDACoutput
-Programmableoutputpolarity
-Selectableinputsource
-ADCsampleandconvertcapability
?PWMmoduleinterface:
-PWMDutyCycleControl
-PWMPeriodControl
-PWMFaultDetect
InterruptController:
?5-cyclelatency
?Uptofiveexternalinterrupts
?Sevenprogrammableprioritylevels
?Fiveprocessorexceptions
High-Speed10-bitADC:
?10-bitresolution
?Upto24inputchannelsgroupedinto12conversionpairs
?Twointernalreferencemonitoringinputsgroupedintoapair
?SuccessiveApproximationRegister(SAR)convertersforparallelconversionsofanalogpairs:
-4MspsfordeviceswithtwoSARs
-2MspsfordeviceswithoneSAR
?Dedicatedresultbufferforeachanalogchannel
?Independenttriggersourcesectionforeachanaloginputconversionpairs
PowerManagement:
?On-chip2.5Vvoltageregulator
?Switchbetweenclocksourcesinrealtime
?Idle,Sleep,andDozemodeswith
CMOSFlashTechnology:
?Low-power,high-speedFlashtechnology
?Fullystaticdesign
?3.3V(±10%)operatingvoltage
?IndustrialandExtendedtemperature
?Lowpowerconsumption
SystemManagement:
?Flexibleclockoptions:
-External,crystal,resonator,internalRC
-Phase-LockedLoop(PLL)with120MHzVCO
-PrimaryCrystalOscillator(OSC)intherangeof3MHzto40MHz
-Secondaryoscillator(SOSC)
-InternalLow-PowerRC(LPRC)oscillatoratafrequencyof32.767kHz
-InternalFastRC(FRC)oscillatoratafrequencyof7.37MHz
?Power-onReset(POR)
?Brown-outReset(BOR)
?Power-upTimer(PWRT)
?OscillatorStart-upTimer(OST)
?WatchdogTimerwithitsRCoscillator
?Fail-SafeClockMonitor
?Resetbymultiplesources
?In-CircuitSerialProgramming?(ICSP?)
?ReferenceOscillatorOutput
ApplicationExamples:
?AC-to-DCConverters
?AutomotiveHID
?BatteryChargers
?DC-to-DCConverters
?DigitalLighting
?InductionCooking
?LEDBallast
?RenewablePower/PureSineWaveInverters
?UninterruptiblePowerSupply(UPS)
圖***33系列方框圖
圖***33系列DSP引擎方框圖
圖***33推薦的最少連接方框圖
圖***33系列數字PFC方框圖
圖***33系列升壓轉換器實現方框圖
圖***33系列單相同步轉換器方框圖
圖***33系列多相同步降壓轉換器方框圖
圖***33系列隔行掃描PFC方框圖
圖***33系列相移全橋轉換器方框圖
圖10.帶PFC和三輸出(12V,5V和3.3V)的AC/DC電源電路圖
Explorer16低成本高效開發板
TheExplorer16isalowcost,efficientdevelopmentboardtoevaluatethefeaturesandperformanceofMicrochip’snewPIC24Microcontroller,thedsPIC33DigitalSignalController(DSC)families,***dwiththeMPLABICD2InCircuitDebuggerorMPLABREALICE,real-timeemulationanddeb***lorer16100-pinfeaturestwointerchangeablePlug-InModules(PIMs),***lorer1644-pinfeaturesaPlug-InModule(PIM)forthePIC24FJ64GA004.
Explorer16開發板主要特性:
?IncludesPIC24FJ128GA010andthedsPIC33FJ256GP710DSCDigitalSignalControllerPIMs(100-pinversion)orthePIC24FJ64GA004PIM(44-pinversion).
?Alpha-numeric16x2LCDdisplay
?InterfacestoMPLABICD2,MPLABREALICE,USB,andRS-232
?IncludesMicrochip’sTC1047Ahighaccuracy,analogoutputtemperaturesensor
?Expansionconnectortoaccessfulldevicespin-outandbreadboardprototypingarea
?PICTailTMPlusconnectorforexpansionboards
?FulldocumentationCDincludesuser’sguide,schematicsandPWBlayout
圖***er16開發板外形圖
圖***er16開發板電路圖(1)
圖***er16開發板電路圖(2)
圖***er16開發板電路圖(3)
圖***er16開發板電路圖(4)
圖***er16開發板電路圖(5)
圖***er16開發板電路圖(6)
詳情請見:
***/en/DeviceDoc/***
和
***/en/DeviceDoc/DM240001%20BOM%20and%***，最終用戶并沒有任何觸電的危險。二級產品都是隔離型的，很有發展前景，該系統能有效地實現對燈的智能控制，控制芯片增加PWM的占空比，
圖4中空鋁管的半塑半鋁的LED日光燈燈管
這種半圓柱的表面積為：2πR*h/2=πR*h。對于T8燈管來說，。