光耦设计裕度的计算

光耦设计裕度的计算CalculationofDesignMarginforCTRofOptocouplers.Author:KevinWildashLastupdated:01Sept1998File:ctr1.doc1.Introduction:Optocouplersareusedinswitchmodepowersupplyunits(PSU)toisolatesignalswhichcrosstheprimarytosecondaryisolationboundary.Typicalusesareinthefeedbackandshutdowncircuits.SuchcircuitsarecriticaltothecorrectoperationofthePSUandfortheprotectionofthecustomer'sequipment.Sincetheperformanceofanoptocouplerdegradeswithage,itisnotsufficienttoassumethatifaPSUisworkingtodaythatitwillthereforebeworkingcorrectlytomorrow.Acalculationofthepredictedperformanceisnecessary.Thispaperdetailsaprocedurewhichwillallowtheeng