Troubleshooting-Switching-Power-Converters-《开关电源故障

TroubleshootingSwitchingPowerConvertersThispageintentionallyleftblankTroubleshootingSwitchingPowerConvertersAHands-onGuideBySanjayaManiktalaAMSTERDAM•BOSTON•HEIDELBERG•LONDONNEWYORK•OXFORD•PARIS•SANDIEGOSANFRANCISCO•SINGAPORE•SYDNEY•TOKYONewnesisanimprintofElsevierNewnesisanimprintofElsevier30CorporateDrive,Suite400,Burlington,MA01803,USALinacreHouse,JordanHill,OxfordOX28DP,UKCopyright©2008byElsevierInc.Allrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformorbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofthepublisher.PermissionsmaybesoughtdirectlyfromElsevier’sScience&TechnologyRightsDepartmentinOxford,UK:phone:[phone],fax:[phone],E-mail:[e-mail]questonlineviatheElsevierhomepage(),byselecting“Support&Contact”then“CopyrightandPermission”andthen“ObtainingPermissions.”Recognizingtheimportanceofpreservingwhathasbeenwritten,Elsevierprintsitsbooksonacid-freepaperwheneverpossible.LibraryofCongressCataloging-in-PublicationDataManiktala,Sanjaya.Troubleshootingswitchingpowerconverters:ahands-onguide/BySanjayaManiktala.p.cm.Includesbibliographicalreferencesandindex.ISBN978-0-7506-8421-7(hardcover:alk.paper)1.Electriccurrentconverters.2.Semiconductorswitches.3.Switchingpowersupplies.I.Title.TK7872.C8M262007621.31'7––dc222007023364BritishLibraryCataloguing-in-PublicationDataAcataloguerecordforthisbookisavailablefromtheBritishLibrary.ISBN:978-0-7506-8421-7ForinformationonallNewnespublicationsvisitourWebsiteat||:TwoSidesoftheSameCoin.............................1LeaveYourPastPerceptionsBehind........................................2ChooseYourFriendsCarefully.............................................4FindingSolutionsthatConverge............................................9TheRippleEffectinPowerSupplies........................................10ExperienceDoesCount;NoIfs,Ands,orButsaboutThat.......................11NeverIgnoreaProblemUntilItIsTooLate..................................13KnowYourInstrumentsWell..............................................14Heatseekers:OntheRoadwithSymptomaticTroubleshooting....................14CausalityCanBetheFirstCasualty.........................................19To“Errr”IsHuman......................................................23Learnfrom(Their)Mistakes...............................................25TheProblemwithProblemSolving.........................................26Chapter2:High-FrequencyEffectsandtheImportanceofInputDecoupling....33Lies,DamnLies,andSchematics...........................................33OccupationalHazards....................................................42WatchtheFeedbackTraceClosely..........................................44PhysicalDistancesBecomeCritical.........................................45EstimatingHarmonicAmplitudes...........................................47High-FrequencyInputDecoupling..........................................48Don’tForgettoPlacethat0.1μFCeramicCapacitorReallyClosetotheIC.........49YouNeedBulkCapacitance,Too...........................................50WhereIsthe“Missing”CurrentComingFrom?...............................51CheckYourBenchPowerSupply...........................................55LackofBulkCapacitanceand/orTooMuchESRCanPlayHavoc................56SingleCeramicCapacitorforBothNoiseandRipple?..........................58viTheControlAlsoNeedsaCleanSupplyRail.................................60BoostTopologyDecouplingIsSlightlyDifferent..............................60Chapter3:OutputNoiseandFiltering................................63MeasuringOutputNoiseandRipple.........................................63Chapter4:UsingCapacitorsWisely..................................79Introduction............................................................79Part1:AluminumElectrolytics.............................................79Part2:CeramicCapacitors................................................93Chapter5:MaximizingtheEffectivenessoftheGroundPlane...............109HowtoParallelOutputCapacitorsforProperSharing..........................109IntegratedSwitcherICSolutionsVersusControllerICSolutions..................114QuickCheckonCurrentthroughAluminumCapacitors.........................114SecondarySideTraceInductancesandTheirImpactonEfficiency................115CurrentReturnPathsintheGroundPlane....................................117ParallelingTracestoReduceInductance.....................................120Chapter6:PrintedCircuitBoardLayoutforAC-DCandDC-DCConverters........................