L4995中文资料

December2007Rev61/3333L49955V,500mAlowdropvoltageregulatorFeatures■OperatingDCsupplyvoltagerange5.6Vto31V■Lowdropoutvoltage■Lowquiescentcurrentconsumption■Resetcircuitsensingofoutputvoltagedownto1V■Programmableresetpulsedelaywithexternalcapacitor■Programmablewatchdog(a)timerwithexternalcapacitor■Thermalshutdownandshortcircuitprotection■Widetemperaturerange(Tj=-40°Cto150°C)■Enable(a)inputforenabling/disablingthevoltageregulatorDescriptionL4995isafamilyofmonolithicintegrated5Vvoltageregulatorswithalowdropvoltageatcurrentsofupto500mA,availableinboth12and24pinpackages.Theoutputvoltageregulatingelementconsistsofap-channelMOSandregulationisperformedregardlessofinputvoltagetransientsofupto40V.Thehighprecisionoftheoutputvoltageisobtainedusingapre-trimmedreferencevoltage.TheL4995familyisprotectedagainstshortcircuitandover-temperatureprotectionswitchesoffthedevicesinthecaseofextremelyhighpowerdissipation.■TheL4995integratestheWatchdog,EnableandexternallyprogrammableResetcircuits.■TheL4995AfeaturestheexternallyprogrammableResetandEnable.■FinallytheL4995RfeaturestheexternallyprogrammableReset.Thecombinationofsuchfeaturesmakesthisdeviceparticularlyflexibleandsuitabletosupplymicroprocessorsystemsinautomotiveapplications.a.WatchdogandEnablefacilitiesareavailableaccordingtoTable1:DevicesummaryMaxDCsupplyvoltageVS40VMaxoutputvoltagetolerance∆V0+/-2%MaxdropoutvoltageVdp500mVOutputcurrentI0500mAQuiescentcurrentIqn3µA(1)1.TypicalvaluewithregulatordisabledPowerSSO-12PowerSSO-24Table1.DevicesummaryPackageOrdercodesTubeTape&reelPowerSSO-12(exposedpad)L4995J-L4995AJ-L4995RJL4995JTR-L4995AJTR-L4995RJTRPowerSSO-24(exposedpad)L4995K-L4995AK-L4995RKL4995KTR-L4995AKTR-L4995RKTRP/NWatchdogResetEnableL4995J-L4995KXXXL4995AJ-L4995AK-XXL4995RJ-L4995RK-X-™thermaldata.................................194.2PowerSSO-24™thermaldata.................................225Packageandpackinginformation.............................255.1ECOPACK®packages.......................................255.2PowerSSO-12™packinginformation............................295.3PowerSSO-24™packinginformation............................306Revisionhistory...........................................31L4995Listoftables3/33ListoftablesTable1.Devicesummary..........................................................1Table2.Pinsdescriptions..........................................................6Table3.Absolutemaximumratings..................................................8Table4.Thermaldata.............................................................9Table5.General.................................................................9Table6.Reset.................................................................10Table7.Watchdog..............................................................11Table8.Enable.................................................................11Table9.PowerSSO-12™thermalparameter..........................................21Table10.PowerSSO-24™thermalparameter..........................................24Table11.PowerSSO-12™mechanicaldata...........................................26Table12.PowerSSO-24™mechanicaldata...........................................27Table13.Documentrevisionhistory.................................................31ListoffiguresL49954/33ListoffiguresFigure1.BlockdiagramofL4995....................................................5Figure2.BlockdiagramofL4995A...................................................5Figure3.BlockdiagramofL4995R...................................................6Figure4.Pinsconfigurations(L4995).................................................7Figure5.Outputvoltagevs.Tj......................................................12Figure6.Outputvoltagevs.Vs.....................................................12Figure7.DropVoltagevs.OutputCurrent............................................12Figure8.Currentconsumptionvs.OutputCurrent......................................12Figure9.Currentconsumptionvs.InputVoltage........................................12Figure10.Currentlimitationvs.Tj....................................................12Figure11.Currentlimitationvs.InputVoltage