LM185-Tkool Electronics

Tkool Electronics

DescriptionLM317isaadjustable3-terminalpositive-voltageregulator,thisbolgcoversLM317regulatoralternative,datasheet,applications,featuresandotherinformationonhowtouseandwheretousethisdevice.ABasicIntroductiontoLM317VoltageRegulatorCatalogDescriptionLM317PinoutLM317FeaturesLM317ApplicationsLM317CircuitLM317ParametersLM317CADModelLM317AdvantageLM317ElectricalCharacteristicsLM317PackageLM317AlternativesLM317EquivalentsWheretouseLM317HowtouseLM317LM317ManufacturerComponentDatasheetFAQOrdering&QuantityLM317PinoutPinNumberPinNameDescription1AdjustThispinsadjuststheoutputvoltage2OutputVoltage(Vout)Theregulatedoutputvoltagesetbytheadjustpincanbeobtainedfromthispin3InputVoltage(Vin)TheinputvoltagewhichhastoberegulatedisgiventothispinLM317FeaturesOutputvoltagerangeadjustablefrom1.25Vto37VOutputcurrentgreaterthan1.5AInternalshort-circuitcurrentlimitingThermaloverloadprotectionOutputsafe-areacompensationLM317ApplicationsATCAsolutionsDLP:3Dbiometrics,hyperspectralimaging,opticalnetworking,andspectroscopyDVRandDVSDesktopPCsDigitalsignageandstillcamerasECGelectrocardiogramsEVHEVchargers:levels1,2,and3ElectronicshelflabelsEnergyharvestingEthernetswitchesFemtobasestationsFingerprintandirisbiometricsHVAC:heating,ventilating,andairconditioningHigh-speeddataacquisitionandgenerationHydraulicvalvesIPphones:wiredandwirelessIntelligentoccupancysensingMotorcontrols:brushedDC,brushlessDC,lowvoltage,permanentmagnet,andsteppermotorsPoint-to-pointmicrowavebackhaulsPowerbanksolutionsPowerlinecommunicationmodemsPoweroverethernet(PoE)PowerqualitymetersPowersubstationcontrolsPrivatebranchexchanges(PBX)ProgrammablelogiccontrollersRFIDreadersRefrigeratorsSignalorwaveformgeneratorsSoftware-definedradios(SDR)Washingmachines:high-endandlow-endX-rays:baggagescanners,medical,anddentalLM317CircuitLM317ParametersOutputoptionsAdjustableOutputIout(Max)(A)1.5Vin(Max)(V)40Vin(Min)(V)3Vout(Max)(V)37Vout(Min)(V)1.25Noise(uVrms)38Iq(Typ)(mA)5ThermalresistanceJA(C/W)24Approx.price(US$)1ku|0.14Loadcapacitance(Min)(F)0RatingCatalogRegulatedoutputs(#)1FeaturesAccuracy(%)5PSRR@100KHz(dB)38Dropoutvoltage(Vdo)(Typ)(mV)2000Operatingtemperaturerange(C)0to125IhsManufacturerTEXASINSTRUMENTSINCBrandNameTexasInstrumentsLM317CADModelPackagePinsDownloadDDPAK/TO-263(KTT)3ViewoptionsSOT-223(DCY)4ViewoptionsTO-220(KCS)3ViewoptionsTO-220(KCT)3ViewoptionsLM317ElectricalCharacteristicsOverrecommendedrangesofoperatingvitualjunctiontemperature(unlessotherwisenoted)LM317PackageDDPAK/TO-263(KTT)SOT-223(DCY)TO-220(KCS)TO-220(KCT)LM317AlternativesSharethesamefunctionalityandpinoutbutisnotanequivalenttothecompareddevice:LM7805,LM7806,LM7809,LM7812,LM7905,LM7912,LM117V33,XC6206P332MR.LM317EquivalentsLT1086,LM1117(SMD),PB137,LM337(NegativeVariableVoltageregulator)WheretouseLM317WhenitcomestovariablevoltageregulationrequirementsLM317wouldmostlikelybethefirstchoice.Apartfromusingitasavariablevoltageregulator,itcanalsobeusedasafixedvoltageregulator,currentlimiter,Batterycharger,ACvoltageregulatorandevenasanadjustablecurrentregulator.OnenotabledrawbackofthisICisthatithasavoltagedropofabout2.5acrossitduringregulation,soifyoulookingtoavoidthatproblemlookintotheotherequivalentICsgivenabove.So,ifyouarelookingforavariablevoltageregulatortodelivercurrentupto1.5AthenthisregulatorICmightbetherightchoiceforyourapplication.HowtouseLM317LM317isa3-terminalregulatorICanditisverysimpletouse.Ithasmanyapplicationcircuitsinitsdatasheet,butthisICisknownforbeingusedasavariablevoltageregulator.So,letslookintohowtousethisICasavariablevoltageregulator.AssaidearliertheIChas3pins,inwhichtheinputvoltageissuppliedtopin3(VIN)thenusingapairofresistors(potentialdivider)wesetavoltageatpin1(Adjust)whichwilldecidetheoutputvoltageoftheICthatisgivenoutatpin2(VOUT).Nowtomakeitactasavariablevoltageregulatorwehavetosetvariablevoltagesatpin1whichcanbedonebyusingapotentiometerinthepotentialdivider.Thebelowcircuitisdesignedtotake12V(youcansupplyupto24V)asinputandregulateitfrom1.25Vto10V.TheResistorR1(1K)andthepotentiometer(10k)togethercreatesapotentialdifferenceatadjustpinwhichregulatestheoutputpinaccordingly.TheformulaetocalculatetheOutputvoltagebasedonthevalueofresistorsisVOUT=1.25(1+(R2/R1))Now,letsverifythisformulafortheabovecircuit.ThevalueofR1is1000ohmsandthevalueofR2(potentiometer)is5000becauseitisa10kpotentiometerplacedat50%(50/100of1000is5000).Vout=1.25(1+(5000/1000))=1.256=7.5VAndthesimulationshows7.7Vwhichisprettymuchclose.Youcanvarytheoutputvoltagebysimplyvaryingthepotentiometer.Inourcircuit,amotorisconnectedasaloadwhichconsumesaround650mAyoucanconnectanyloadupto1.5A.Thesameformulaecanalsobeusedtocalculatethevalueofresistorforyourequiredoutputvoltage.Oneeasywaytodothisistousethisonlinecalculatortorandomlysubstitutethevalueofresistorsyouhaveandcheckwhichoutputvoltageyouwillget.LM317ManufacturerTexasInstrumentsInc.(TI)isanAmericantechnologycompanythatdesignsandmanufacturessemiconductorsandvariousintegratedcircuits,whichitsellstoelectronicsdesignersandmanufacturersglobally.ItsheadquartersareinDallas,Texas,UnitedStates.TIisoneofthetoptensemiconductorcompaniesworldwide,basedonsalesvolume.TexasInstrumentssfocusisondevelopinganalogchipsandembeddedprocessors,whichaccountsformorethan80%oftheirrevenue.TIalsoproducesTIdigitallightprocessing(DLP)technologyandeducationtechnologyproductsincludingcalculators,microcontrollersandmulti-coreprocessors.Todate,TIhasmorethan43,000patentsworldwide.ComponentDatasheetLM317DatasheetFAQWhatislm317usedfor?TheLM317servesawidevarietyofapplicationsincludinglocal,oncardregulation.Thisdevicecanalsobeusedtomakeaprogrammableoutputregulator,orbyconnectingafixedresistorbetweentheadjustmentandoutput,theLM317canbeusedasaprecisioncurrentregulator.Whatisthemaximuminputvoltageoflm317?TheLM317isanadjustablevoltagelinearregulatorthatcanoutput1.2537Vatupto1.5Acurrentwithaninputvoltagerangeof340V.Whatisthedifferencebetweenlm317andlm317t?Member.Thereisnofunctionaldifferenceastheyareoneinthesame.TheTattheendjustindicatesthatitsinaTO-220package.Theyusuallytagonextrathingsafterthepartnametoreferencethingslikepackage,temprange,etc.Islm317atransistor?TheLM317isanadjustablethree-terminalpositive-voltageregulatorcapableofsupplyingmorethan1.5Aoveranoutput-voltagerangeof1.25Vto32V....Byusingaheat-sinkedpasstransistorsuchasa2N3055(Q1)wecanproduceseveralampsofcurrentfarabovethe1.5ampsoftheLM317.Howdoesanlm317work?Thecircuitconsistsofalow-sideresistorandhigh-sideresistorconnectedinseriesformingaresistivevoltagedividerwhichisapassivelinearcircuitusedtoproduceanoutputvoltagewhichisafractionofitsinputvoltage.WhatisIClm317?TheLM317deviceisanadjustablethree-terminalpositive-voltageregulatorcapableofsupplyingmorethan1.5Aoveranoutput-voltagerangeof1.25Vto37V.Itrequiresonlytwoexternalresistorstosettheoutputvoltage.Thedevicefeaturesatypicallineregulationof0.01%andtypicalloadregulationof0.1%.HowdoIknowifmylm317isworking?Testinglm317t.Ifyoulooktotheic,thelegstowardsyou,therightoneistheinputpin.youmustseeadifferenceofminimum1.2Vbetweenthetwopins,otherwisetheICisfaulty.furthermore,thefirsttestistoseeifyouhaveinputvoltage!Whatistheworkingpricipleoflm317?LM317worksonaverysimpleprinciple.Itisavariablevoltageregulatori.e.supportsdifferentoutputvoltagelevelsforaconstantappliedinputvoltagesupply.HowtomakeasimplevoltageregulatorcircuitusingLM317?