EUP3484

EUP3484DS3484Ver1.0Mar.201013A,30V,340KHzSynchronousStep-DownConverterDESCRIPTIONTheEUP3484isasynchronouscurrentmodebuckregulatorcapableofdriving3Acontinuousloadcurrentwithexcellentlineandloadregulation.TheEUP3484canoperatewithaninputrange4.5Vto30Vandtheoutputcanbeexternallysetfrom0.925Vto20Vwitharesistordivider.Faultconditionprotectionincludescycle-by-cyclecurrentlimitingandthermalshutdown.Inshutdownmodetheregulatordraws1µAofsupplycurrent.Programmablesoft-startminimizestheinrushsupplycurrentandtheoutputovershootatinitialstartup.TheEUP3484requireaminimumnumberofexternalcomponents.TypicalApplicationCircuitFEATURESz3AOutputCurrentz35VInputSurgeProtectionzIntegrated160mΩ/110mΩDMOSSwitchesz4.5Vto30VInputOperatingRangezOutputAdjustablefrom0.925Vto20VzUpto95%Efficiencyz1µAShutdownCurrentzFixed340KHzFrequencyzProgrammableSoft-StartzThermalShutdownandOvercurrentProtectionzInputSupplyOvervoltageandUndervoltageLockoutzAvailableinSOP-8(EP)PackagezRoHSCompliantand100%Lead(Pb)-FreeHalogen-FreeAPPLICATIONSzDistributedPowerSystemszNetworkingSystemszPCMonitorszPortableElectronicsFigure1.12Vto3.3V/5VApplicationCircuitEUP3484DS3484Ver1.0Mar.20102TypicalApplicationCircuit(continued)Figure2.24Vto3.3V/5VapplicationcircuitPinConfigurationsPackageTypePinConfigurationsSOP-8(EP)PinDescriptionPINPINDESCRIPTION1BSHigh-SideGateDriveBoostInput.BSsuppliesthedriveforthehigh-sideN-ChannelDMOSswitch.Connecta0.01µForgreatercapacitorfromSWtoBStopowerthehighsideswitch.2INInputSupplyPin.INsuppliesthepowertotheIC,aswellasthestep-downconverterswitches.DriveINwitha4.5Vto30Vpowersource.BypassINtoGNDwithasuitablylargecapacitortominimizeinputrippletotheIC.SeeInputCapacitorSectionoftheapplicationsnotes.3SWPowerSwitchingOutput.ConnecttheoutputLCfilterfromSWtotheoutputload.4GNDGround.5FBOutputFeedbackInput.FBsensestheoutputvoltageandregulatesit.DriveFBwitharesistivevoltagedividerconnectedtoitfromtheoutputvoltage.Thefeedbackthresholdis0.925V.SeeSettingtheOutputVoltage.6COMPLoopcompensationInput.ConnectaseriesRCnetworkfromCOMPtoGNDtocompensatetheregulationcontrolloop.SeeCompensation.7ENEnableInput.ENisalogicinputthatcontrolstheregulatoronoroff.DriveENhightoturnontheregulator;lowtoturnitoff.Don’tleaveENpinfloating.DirectlyconnectENtoIN(orthrougharesistance)forautomaticstartup.8SSSoft-StartControlInput.Connectanexternalcapacitortoprogramthesoft-start.Ifunused,leaveitopen,whichmeansinternalsoft-startfunction.EUP3484DS3484Ver1.0Mar.20103OrderingInformationOrderNumberPackageTypeMarkingOperatingTemperatureRangeEUP3484DIR1SOP-8(EP)xxxxxP3484-40°Cto+85°CEUP3484LeadFreeCode1:LeadFree,Halogen-Free0:LeadPackingR:Tape&ReelOperatingtemperaturerangeI:IndustryStandardPackageTypeD:SOPBlockDiagramFigure3.FunctionalBlockDiagramEUP3484DS3484Ver1.0Mar.20104AbsoluteMaximumRatings(1)„SupplyVoltage(VIN)---------------------------------------------------------0.3Vto+35V„EnableVoltage(VEN)-------------------------------------------------------0.3Vto+35V„SwitchVoltages(VSW)-------------------------------------------------------1VtoVIN+0.3V„BootVoltage(VBS)--------------------------------------------------VSW-0.3VtoVSW+6V„AllOtherPins-----------------------------------------------------------------------0.3Vto+6V„JunctionTemperature--------------------------------------------------------------------150°C„LeadTemperature--------------------------------------------------------------260°C„StorageTemperature---------------------------------------------------------65°Cto+150°C„OutputVoltageVOUT-----------------------------------------------------------0.925Vto20V„ThermalResistanceθJA(SOP-8_EP)------------------------------------------------------------60°C/WRecommendOperatingConditions(2)„InputVoltageVIN---------------------------------------------------------------------4.5Vto30V„AmbientOperatingTemp------------------------------------------------------40°Cto+85°CNote(1):Stressbeyondthoselistedunder“AbsoluteMaximumRatings”maydamagethedevice.Note(2):Thedeviceisnotguaranteedtofunctionoutsidetherecommendedoperatingconditions.ElectricalCharacteristicsThe●denotespecificationswhichapplyoverthefulloperatingtemperaturerange,otherwisespecificationareVIN=12V,TA=25°Cunlessotherwisespecified.EUP3484ParameterConditionsMinTypMax.UnitShutdownSupplyCurrentVEN=0V15µASupplyCurrentVFB=1V0.450.9mA0.9070.9250.943FeedbackVoltage4.5≤VIN≤30V●0.8970.9250.953VErrorAmplifierVoltageGain360V/VErrorAmplifierTransconductance∆IC=±10µA800µA/VHigh-SideSwitchOn-Resistance160mΩLow-SideSwitchOn-Resistance110mΩHigh-SideSwitchLeakageCurrentVEN=0V,VSW=0V5µAUpperSwitchCurrentLimitMinimumDutyCycle3.85.5ALowerSwitchCurrentLimitFromDraintoSource1.1ACOMPtoCurrentSenseTransconductance7.5A/VOscillationFrequency300340380KHzShortCircuitOscillationFrequencyVFB=0V110KHzMaximumDutyCycleVFB=0.7V90%0.621.11.52ENDisableThreshold●0.361.11.76V2.32.52.8ENLockoutThresholdVENRising●22.53VENLockoutThresholdHysteresis120mVInputUnderVoltageLockoutThresholdVINFalling3.84.14.4VInputOverVoltageLockoutThresholdVINRising35VInputOverVoltageLockoutThres