西门康IGBT驱动详解

IGBTGateDriverCalculation GateDriverRequirement WhatisthemostimportantrequirementforanIGBTdriver GatePeakcurrent Conditionsforasafetyoperation WhichgatedriverissuitableforthemoduleSKM200GB128D Designparameters fsw 10kHzRg reverserecoverycurrentDiodeshouldbe 1 5xIdiodeby80degreecase130Ax1 5 195A Gateresistorinrangeof test gateresistor Howtofindtherightgateresistor Rg 7Ohm TwogateresistorsarepossibleforturnonandturnoffRon 7OhmRoff 10Ohm 195A maxreverserecoverycurrent DifferencebetweenTrench andSPTTechnology TrenchTechnologyneedsasmallerGatechargeDriverhastoprovideasmallerGatechargeSPTTechnologyneedsmoreGatechargecomparedtoTrenchTechnologyDriverhastoprovideahigherGatecharge Driverperformance differentIGBTtechnologiesneedsdifferentgatecharge TrenchIGBTwithsamechipcurrent Gatechargeis2 3uC Driverperformance differentIGBTtechnologiesneedsdifferentgatecharge SPTIGBTwithsamechipcurrent Gatechargeis3uC Demandsforthegatedriver ThesuitablegatedrivermustprovidetherequiredGatecharge QG powersupplyofthedrivermustprovidetheaveragepowerAveragecurrent IoutAV powersupplyGatepulsecurrent Ig pulse mostimportantattheappliedswitchingfrequency fsw 8 15 1390 DeterminationofGateCharge Gatecharge QG canbedeterminedfromfig 6oftheSEMITRANSdatasheet QG 1390nC Thetypicalturn onandturn offvoltageofthegatedriverisVGG 15VVGG 8V Calculationoftheaveragecurrent Calculationofaveragecurrent IoutAV P U V Vg Vg withP E fsw QG V fsw IoutAV QG fsw 1390nC 10kHz 13 9mA Absolutevalue Powersupplyrequirements GatechargeThepowersupplyorthetransformermustprovidetheenergy Semikronisusingpulsetransformerforthepowersupply wemustconsiderthetransformedaveragepowerfromthetransformer AveragecurrentIsrelatedtothetransformer Calculationofthepeakgatecurrent ExaminationofthepeakgatecurrentwithminimumgateresistanceE g RG on RG off 7 Ig puls V RG Rint 23V 7 1 2 9A Pulsepowerratingofthegateresistor Ptotal GateresistorPpulseGateresistor IoutAVx VMoreinformation Theproblemoccurswhentheuserforgetsaboutthepeakpowerratingofthegateresistor Thepeakpowerratingofmany ordinary SMDresistorsisquitesmall ThereareSMDresistorsavailablewithhigherpeakpowerratings Forexample ifyoutakeanSKDdriverapart youwillseethatthegateresistorsareinadifferentSMDpackagetoalltheotherresistors exceptoneortwootherplacesthatalsoneedhighpeakpower Theproblemwaslessobviouswiththroughholecomponentssimplybecausetheresistorswerephysicallybigger ThePhilipsresistordatabookhasagoodsectiononpeakpowerratings Choiceofthesuitablegatedriver TheabsolutemaximumratingsofthesuitablegatedrivermustbeequalorhigherthantheappliedandcalculatedvaluesGatechargeQG 1390nCAveragecurrentIoutAV 13 9mAPeakgatecurrentIg pulse 2 9ASwitchingfrequencyfsw 10kHzCollectorEmittervoltageVCE 1200VNumberofdriverchannels 2 GBmodule dualdriver Comparisonwiththeparametersinthedriverdatasheet Calculatedandappliedvalues Ig pulse 2 9A Rg 7 RintIoutAV 13 9mAfsw 10kHzVCE 1200VQG 1390nC Accordingtotheappliedandcalculatedvalues thedrivere g SKHI22AisabletodriveSKM200GB128D PCBDriverandPCBmountableDriverforsingle halfbridge sixpackmodulesintegratedpotential freepowersupplyswitchingfrequencyupto100kHzoutputpeakcurrentupto30AGatechargeupto30 Cdv dtcapabilityupto75kV shighEMIimmunityTTL anCMOS compatibleinputsandoutputswithpotentialisolationviaoptocouplerortransformer isolationupto4kVAC protection interlock shortpulsesuppression shortcircuitprotectionviaVCE monitoring undervoltagemonitoring errormemoryanderrorfeedback SEMIDRIVER Productoverview importantparameters DrivercoreforIGBTmodules SimpleAdaptableExpandableShorttimetomarketTwoversionsSKYPER standardversion SKYPER PRO premiumversion AssemblyonSEMiXTM3 ModularIPM SKYPERDriverboardSEMIX3IGBThalfbridgewithspringcontacts SKYPER morethanasolution modularIPMusingSEMiX withadapterboard solderdirectlyinyourmainboard take3for6 packs SelectionoftherightIGBTdriver Advice Problem1 Crossconduction Lowimpedance Crossconductionbehavior vCE T1 t iC T1 t VCC IO 0 t vGE T1 t vGE T2 t VGE Io VGE th 0 t VGG VCC IO 0 t vCE T2 t vF D2 t iF D2 t iC T2 t T1 D1 T2 D2 iv T2 WhychangesVGE T2whenT1switcheson IGBT Parasiticcapacitances WhentheoutervoltagepotentialVchanges theloadQhastofollowThisleadstoadisplacementcurrentiV Switching DetailedforT2 iv T2 vCE T2 vGE T2 iC T2 RGE T2 CGC T2 DiodeD2switchesoffandtakesoverthevoltageT2 sees thevoltageoverD2asvCE T2 Withthechangedvoltagepotential theinternalcapacitanceschangetheirchargeThedisplacementcurrentiv T2flowsviaCGC T2 RGE T2andthedriver iv T2causesavoltagedropinRGE T2whichisaddedtoVGE T2 IfvGE T2 VGE th thenT2turnson ThereforeSKrecommends VGG 5 8 15V Problem2 gateprotection Z16 18 Gateclamping how Z18 PCBdesignbecausenocableclosetotheIGBT Problem3 boosterforthegatecurrent UseMOSFETforthebooster ForsmallIGBTsisok Problem4 Shortcircuit Overvoltage1200V ischiplevel considerinternalstrayinductance 20V gateemittervoltage considerswitchingbehavioroffreewheelingdiodeOvercurrentPowerdissipationofIGBT shortcircuitcurrentxtime Chiptemperaturelevel Problem5 deadtimebetweentopandbottomIGBT Turnonandturnoffdelaymustbesymetrical Deadtimeexplanation Deadtimeexplanation Example Deadtime 3uslogiclevelTurnondelay1usTurnoffdelay2 5usTd toffdelay tondelay realdeadtimeRealdeadtime 3us 2 5us 1us 1 5us Ourfinalrecommendation IGBTdrivermustprovidethepeakGatecurrentThestrayinductanceshouldbeverysmallinthegatedrivercircuitGate Emi