MOSFET-数据手册详解

©2013FairchildSemiconductorCorporation•10/23/14AN-4163—ShieldedGatePowerTrench®MOSFETDatasheetExplanationIntroductionAMOSFETdatasheetcontainsimportanttechnicalinformationforpowersystemdesignerstochooseproperMOSFETsforspecificapplications.ThisapplicationnoteexplainstheelectricalparametersandgraphsspecifiedindatasheetsPowerTrench®MOSFETs.TheshieldedgatePowerTrenchisFairchild’sadvancedtrenchMOSFETdesigntechnologythatsupportsMOSFETsratedupto300V.Inthisapplicationnote,the100VN-channelFDMS86101Adatasheetisusedforexplanation.1.Drain-to-SourceBreakdownVoltage,BVDSSThebreakdownvoltagebetweenthedrainandthesourceterminal,BVDSS,ismeasuredat250µAdraincurrent,ID,withthegateshortedtothesource,whichturnsofftheMOSFET,asshowninFigure1.Table1providestheminimumvalueofBVDSSat25°Cjunctiontemperature,TJ.TheleveloftheBVDSSisproportionaltotheincreaseofTJpositively.Forexample,thebreakdownvoltagetemperaturecoefficientofFDMS86101A,JTDSSBVis71mV/°Ctypically.IfTJofFDMS86101Areaches100°C,theBVDSSincreasesby5.325V(75°Cx71mV/°C).Formorereliableoperation,specialcautionshouldbetakentonotexceedtheBVDSS;especiallyataninductiveloadcondition.DUTIDDrainGateSourceFigure1.Drain-to-SourceBreakdownVoltageTestCircuitTable1.Drain-to-SourceBreakdownVoltageParametersSymbolParameterConditionsMin.Typ.UnitBVDSSDrain-to-SourceBreakdownVoltageID=250µA,VGS=0V100VJTDSSBVBreakdownVoltageTemperatureCoefficientID=250µA,Referencedto25°C71mV/°C2.Gate-to-SourceVoltage,VGSThesustainablevoltagebetweenthegateandthesourceterminalislimitedtothemaximumvoltage,VGS.Ithasthepositiveandnegative20V,showninTable2,andanygatedrivevoltagemustbelessthanthemaximumVGS.DesignersshouldcheckthedatasheetvalueforreliableoperationsincetheVGSvariesbyMOSFETtechnology.Table2.GatetoSourceVoltageParametersSymbolParameterRatingsUnitVGSGatetoSourceVoltage±20V3.Gate-to-SourceThresholdVoltage,VGS(th)Thegate-to-sourcethresholdvoltage,VGS(th),isdefinedasaminimumgateelectrodebiastoconductthe250µAdraincurrent,ID.Ithasthenegativetemperaturecoefficient,J)(TthGSVsoitisdecreasedasthejunctiontemperature,TJrises.Forexample,whenTJofFDMS86101Abecomes100°C,VGS(th)isreducedby0.675V(75°Cx-9mV/°C).Minimum,typical,andmaximumvaluesarespecifiedinTable3.AN-4163APPLICATIONNOTE©2013FairchildSemiconductorCorporation•10/23/142Table3.Gate-to-SourceThresholdVoltageParametersSymbolParameterTestConditionsMin.Typ.Max.UnitVGS(th)Gate-to-SourceThresholdVoltageVGS=VDS,ID=250µA2.03.14.0VJ)(TthGSVGate-to-SourceThresholdVoltageTemperatureCoefficientID=250µA,Referencedto25°C-9mV/°C4.StaticDrain-to-SourceOnResistance,RDS(on)Thestaticdrain-to-sourceon-resistance,RDS(on),isdescribedatvariousgatevoltages,VGSwhicharegreaterthanthegate-to-sourcethresholdvoltage,VGS(th),anddifferentdraincurrentlevelsinTable4becausetheRDS(on)valuechangesatadifferentamplitudeoftheVGSandthedraincurrent,ID,atajunctiontemperature,TJ.Therearetwographspertainingtothestaticon-resistance.Table4.StaticDrain-to-SourceOnResistanceParametersSymbolParameterConditionsMin.Typ.Max.UnitRDS(on)StaticDrain-to-SourceOnResistanceVGS=10V,ID=13A6.38.0mΩVGS=6V,ID=9.5A8.013.5VGS=10V,ID=13A,TJ=125°C10.313.1Thenormalizeddrain-to-sourceonresistanceisafunctionofIDatagivenVGS,asshowninFigure2.VGSplaysanimportantroleinchangingtheonresistancevalue.WhentheVGSisdecreasedfrom10VGSto5VGSat60AofID,theRDS(on)increasesthreetimes,whichcanbetranslatedto18.9mΩ(3times6.3mΩ)andthemaximumIDissaturatedataround60Awith5VGSduetotheincreasedRDS(on).Figure3showsthenormalizeddrain-to-sourceonresistanceaccordingtoTJ.TheRDS(on)hasapositivetemperaturecoefficient;soatthe125°Cjunctiontemperature,thestaticdrain-to-sourceonresistanceofFDMS86101Aisincreasedby1.63timescomparedtothe25°Cvalue.Therefore,inthecaseofparalleloperation,thedraincurrentcanbewellbalancedamongMOSFETsbecauseincreasingonresistancecausedbyincreasingjunctiontemperaturepreventsthedraincurrentfromflowingthroughonlyoneorafewchannelsofMOSFETsandthenparallelconnectedMOSFETssharethetotaldraincurrent.Figure2.NormalizedOnResistancevs.DrainCurrentandGateVoltageFigure3.NormalizedOnResistancevs.TJByusingtwographsshowingnormalizeddrain-to-sourceonresistancevalues,theRDS(on)graphofFigure4asthefunctionoftheVGSatbothgivenTJandIDprovidestypicalRDS(on)values.Forexample,ifIDis13AandVGSis5Vin25°Cjunctiontemperature,thetypicalRDS(on)is10mΩ.Figure4.OnResistancevs.Gate-to-SourceVoltageAN-4163APPLICATIONNOTE©2013FairchildSemiconductorCorporation•10/23/1435.OperatingandStorageJunctionTemperatureRange,TJTheoperatingandstoragejunctiontemperature,TJindicatestherecommendedtemperaturerangeinwhichaMOSFEToperatesreliablyunderspecifiedelectricalvalues.MostofstandardMOSFETshave-55°Cto+150°CtemperaturerangelikeTable5.Table5.OperatingandStorageJunctionTemperatureParametersSymbolParameterRatingsUnitTJOperatingandStorageJunctionTemperatureRange-55to+150°C6.PowerDissipation,PDThepowerdissipation,PD,isthemaximumallowablepowerlimitofadevice.ThetwoPDparametersaredependenton