Class D Audio Amplifier Output Filter Optimization

Abstract:ThisapplicationnoteexaminestheeffectoftheoutputfilteronaudioClassDamplifierperformance.Switch-modeamplifierssuchastheMAX4295andMAX4297offerimprovedefficiencyovertheirmoretraditionalClassABcounterparts.Byunderstandingtheoperationofthesedevices,themodulationnoisespectrumandtheloudspeakerloadstheyarerequiredtodrive,itispossibletocompletelyeliminatetheoutputfilterwhileretainingtheefficiencybenefitsofClassDamplifiers.Maxim>AppNotes>AMPLIFIERANDCOMPARATORCIRCUITSAUDIOCIRCUITSKeywords:ClassD,audioamplifiers,switchingamplifer,outputfilter,modulationnoise,PWM,filterless,Apr01,2002amplifersAPPLICATIONNOTE624ClassDAudioAmplifierOutputFilterOptimizationAbstract:ThisapplicationnoteexaminestheeffectoftheoutputfilteronaudioClassDamplifierperformance.Switch-modeamplifierssuchastheMAX4295andMAX4297offerimprovedefficiencyovertheirmoretraditionalClassABcounterparts.Byunderstandingtheoperationofthesedevices,themodulationnoisespectrumandtheloudspeakerloadstheyarerequiredtodrive,itispossibletocompletelyeliminatetheoutputfilterwhileretainingtheefficiencybenefitsofClassDamplifiers.Thisarticl