IGBT驱动电路分析

1SemikronHongKongNorbertPluschke07.10.2005IGBTGateDriverCalculationGateDriverRequirement2SemikronHongKongNorbertPluschke07.10.2005WhatisthemostimportantrequirementforanIGBTdriver?GatePeakcurrent3SemikronHongKongNorbertPluschke07.10.2005ConditionsforasafetyoperationWhichgatedriverissuitableforthemoduleSKM200GB128D?Designparameters:fsw=10kHzRg=?reverserecoverycurrentDiodeshouldbe-1.5xIdiodeby80degreecase130Ax1.5=195AGateresistorinrangeof“test–gateresistor”4SemikronHongKongNorbertPluschke07.10.2005Howtofindtherightgateresistor?Rg=7OhmTwogateresistorsarepossibleforturnonandturnoffRon=7OhmRoff=10Ohm195A–maxreverserecoverycurrent5SemikronHongKongNorbertPluschke07.10.2005DifferencebetweenTrench-andSPTTechnologyTrenchTechnologyneedsasmallerGatechargeDriverhastoprovideasmallerGatechargeSPTTechnologyneedsmoreGatechargecomparedtoTrenchTechnologyDriverhastoprovideahigherGatecharge6SemikronHongKongNorbertPluschke07.10.2005Driverperformance–differentIGBTtechnologiesneedsdifferentgatechargeTrenchIGBTwithsamechipcurrentGatechargeis2.3uC7SemikronHongKongNorbertPluschke07.10.2005Driverperformance–differentIGBTtechnologiesneedsdifferentgatechargeSPTIGBTwithsamechipcurrentGatechargeis3uC8SemikronHongKongNorbertPluschke07.10.2005DemandsforthegatedriverThesuitablegatedrivermustprovidetherequiredGatecharge(QG)–powersupplyofthedrivermustprovidetheaveragepowerAveragecurrent(IoutAV)–powersupplyGatepulsecurrent(Ig.pulse)–mostimportantattheappliedswitchingfrequency(fsw)9SemikronHongKongNorbertPluschke07.10.2005-8151390DeterminationofGateChargeGatecharge(QG)canbedeterminedfromfig.6oftheSEMITRANSdatasheetQG=1390nCThetypicalturn-onandturn-offvoltageofthegatedriverisVGG+=+15VVGG-=-8V10SemikronHongKongNorbertPluschke07.10.2005CalculationoftheaveragecurrentCalculationofaveragecurrent:IoutAV=P/UV=+Vg+[-Vg]withP=E*fsw=QG*V*fswIoutAV=QG*fsw=1390nC*10kHz=13.9mAAbsolutevalue11SemikronHongKongNorbertPluschke07.10.2005PowersupplyrequirementsGatechargeThepowersupplyorthetransformermustprovidetheenergy(Semikronisusingpulsetransformerforthepowersupply,wemustconsiderthetransformedaveragepowerfromthetransformer)AveragecurrentIsrelatedtothetransformer12SemikronHongKongNorbertPluschke07.10.2005CalculationofthepeakgatecurrentExaminationofthepeakgatecurrentwithminimumgateresistanceE.g.RG.on=RG.off=7Ig.puls≈V/RG+Rint=23V/7+1=2.9A13SemikronHongKongNorbertPluschke07.10.2005PulsepowerratingofthegateresistorPtotal–GateresistorPpulseGateresistor=IoutAVxVMoreinformation:Theproblemoccurswhentheuserforgetsaboutthepeakpowerratingofthegateresistor.ThepeakpowerratingofmanyordinarySMDresistorsisquitesmall.ThereareSMDresistorsavailablewithhigherpeakpowerratings.Forexample,ifyoutakeanSKDdriverapart,youwillseethatthegateresistorsareinadifferentSMDpackagetoalltheotherresistors(exceptoneortwootherplacesthatalsoneedhighpeakpower).Theproblemwaslessobviouswiththroughholecomponentssimplybecausetheresistorswerephysicallybigger.ThePhilipsresistordatabookhasagoodsectiononpeakpowerratings.14SemikronHongKongNorbertPluschke07.10.2005ChoiceofthesuitablegatedriverTheabsolutemaximumratingsofthesuitablegatedrivermustbeequalorhigherthantheappliedandcalculatedvaluesGatechargeQG=1390nCAveragecurrentIoutAV=13,9mAPeakgatecurrentIg.pulse=2.9ASwitchingfrequencyfsw=10kHzCollectorEmittervoltageVCE=1200VNumberofdriverchannels:2(GBmodule)dualdriver15SemikronHongKongNorbertPluschke07.10.2005ComparisonwiththeparametersinthedriverdatasheetCalculatedandappliedvalues:Ig.pulse=2.9A@Rg=7+RintIoutAV=13.9mAfsw=10kHzVCE=1200VQG=1390nCAccordingtotheappliedandcalculatedvalues,thedrivere.g.SKHI22AisabletodriveSKM200GB128D17SemikronHongKongNorbertPluschke07.10.2005Productoverview(importantparameters)18SemikronHongKongNorbertPluschke07.10.2005DrivercoreforIGBTmodulesSimpleAdaptableExpandableShorttimetomarketTwoversionsSKYPER™(standardversion)SKYPER™PRO(premiumversion)19SemikronHongKongNorbertPluschke07.10.2005AssemblyonSEMiXTM3–ModularIPMSKYPERDriverboardSEMIX3IGBThalfbridgewithspringcontacts20SemikronHongKongNorbertPluschke07.10.2005SKYPER™–morethanasolutionmodularIPMusingSEMiX®withadapterboardsolderdirectlyinyourmainboardtake3for6-packs21SemikronHongKongNorbertPluschke07.10.2005SelectionoftherightIGBTdriverAdvice22SemikronHongKongNorbertPluschke07.10.2005Problem1---------------------CrossconductionLowimpedance23SemikronHongKongNorbertPluschke07.10.2005CrossconductionbehaviorvCE,T1(t)iC,T1(t)VCCIO0tvGE,T1(t)vGE,T2(t)VGE,IoVGE(th)0tVGG+VCCIO0tvCE,T2(t)=vF,D2(t)iF,D2(t),iC,T2(t)T1D1T2D2iv,T2WhychangesVGE,T2whenT1switcheson?24SemikronHongKongNorbertPluschke07.10.2005IGBT-ParasiticcapacitancesdtdvCiVCQvWhentheoutervoltagepotentialVchanges,theloadQhastofollowThisleadstoadisplacementcurrentiV25SemikronHongKongNorbertPluschke07.10.2005Switching:DetailedforT2dtdvCiT2CE,T2GC,T2v,iv,T2T2GE,T2v,T2GE,RivvCE,T2vGE,T2iC,T2RGE,T2CGC,T2vCE,T2(t)VCC0t0tiC,T2(t)iv,T2(t)vGE,T2(t)VGE(th)0tVGG+DiodeD2switchesoffandtakesoverthevoltageT2“sees”thevoltageoverD2as