LinearLTC3787大功率高效多相同步升压控制方案关键词：电源管理,DC/DC转换器,PolyPhaseLinear公司的LTC3787是大功率高效多相同步升压控制器，效率高达97%，因而不需要散热器。LTC3787集成了两个N-沟功率MOSFET，两相工作降低了输入和输出电容以及电源所引起的噪音，输电电压从4.5V到38V，输出电压高达60V，输出电流可高达10A，可以配置成2/3/4/6/12相工作，主要用在工业，汽车，医疗和军用设备。本文介绍了LTC3787主要特性，方框图，2/3/4/6/12相工作配置图以及12-24V/10A两相同步升压转换器和高效四相单输出升压转换器等多种应用电路。LTC3787:HighPowerPolyphase®SynchronousBoostControllerEliminatesHeatSinkwith97%EfficiencyTheLTC®3787isahighperformancePolyPhase®singleoutputsynchronousboostconvertercontrollerthatdrivestwoN-channelpowerMOSFETstagesout-of-phase.Multiphaseoperationreducesinputandoutputcapacitorrequirementsandallowstheuseofsmallerinductorsthanthesingle-phaseequivalent.Synchronousrectificationincreasesefficiency,reducespowerlossesandeasesthermalrequirements,enablinghighpowerboostapplications.A4.5Vto38Vinputsupplyrangeencompassesawiderangeofsystemarchitecturesandbatterychemistries.Whenbiasedfromtheoutputoftheboostconverteroranotherauxiliarysupply,theLTC3787canoperatefromaninputsupplyaslowas2.5Vafterstart-up.Theoperatingfrequencycanbesetfora50kHzto900kHzrangeorsynchronizedtoanexternalclockusingtheinternalPLL.PolyPhaseoperationallowstheLTC3787tobeconfiguredfor2-,3-,4-,6-and12-phaseoperation.TheSSpinrampstheoutputvoltageduringstart-up.ThePLLIN/MODEpinselectsBurstMode®operation,pulse-skippingmodeorforcedcontinuousmodeatlightloads.LTC3787主要特性:2-PhaseOperationReducesRequiredInputandOutputCapacitanceandPowerSupplyInducedNoiseSynchronousOperationforHighestEfficiencyandReducedHeatDissipationWideVINRange:4.5Vto38V(40VAbsMax)andOperatesDownto2.5VAfterStart-UpOutputVoltageUpto60V±1%1.200VReferenceVoltageRSENSEorInductorDCRCurrentSensing100%DutyCycleCapabilityforSynchronousMOSFETLowQuiescentCurrent:135μAPhase-LockableFrequency(75kHzto850kHz)ProgrammableFixedFrequency(50kHzto900kHz)PowerGoodOutputVoltageMonitorLowShutdownCurrent,IQ<8μAInternalLDOPowersGateDrivefromVBIASorEXTVCCThermallyEnhancedLowProfile28-Pin4mm×5mmQFNPackageandNarrowSSOPPackageLTC3787应用:IndustrialAutomotiveMedicalMilitary图1.LTC3787方框图图2.LTC378712-24V/10A两相同步升压转换器图3.LTC3787三相工作框图图4.LTC3787四相工作框图图5.LTC3787六相工作框图图6.LTC3787十二相工作框图图7.LTC3787推荐PCB布局框图图8.LTC3787高效二相24V升压转换器图9.LTC3787高效二相28V升压转换器图10.LTC3787高效二相48V升压转换器图11.LTC3787带电感DCR电流检测的高效二相24V升压转换器AO-Electronics傲壹电子官网：www.aoelectronics.com中文网：www.aoelectronics.cn图12.LTC3787高效四相单输出升压转换器
