WM8731

WM8731PortableInternetAudioCODECwithHeadphoneDriverandProgrammableSampleRatesAdvancedInformation,Rev2.0,February2001WOLFSONMICROELECTRONICSLTDLuttonCourt,BernardTerrace,Edinburgh,EH89NX,UKTel:[phone]Fax:[phone]Email:[e-mail]2001WolfsonMicroelectronicsLtd.DESCRIPTIONTheWM8731isalowpowerstereoCODECwithanintegratedheadphonedriver.ItofferstheusertheuniqueabilitytoindependentlyprogramtheADCandDACsampleratesfromasingleclocksource.TheWM8731isdesignedspecificallyforportableMP3audioandspeechplayersandrecorders.TheWM8731isalsoidealforMD,CD-RWmachinesandDATrecorders.Stereolineandmonomicrophonelevelaudioinputsareprovided,alongwithamutefunction,programmablelinelevelvolumecontrolandabiasvoltageoutputsuitableforanelectrettypemicrophone.Stereo24-bitmulti-bitsigmadeltaADCsandDACsareusedwithoversamplingdigitalinterpolationanddecimationfilters.Digitalaudioinputwordlengthsfrom16-32bitsandsamplingratesfrom8kHzto96kHzaresupported.Stereoaudiooutputsarebufferedfordrivingheadphonesfromaprogrammablevolumecontrol,lineleveloutputsarealsoprovidedalongwithanti-thumpmuteandpowerup/downcircuitry.Thedeviceiscontrolledviaa2or3wireserialinterface.Theinterfaceprovidesaccesstoallfeaturesincludingvolumecontrols,mutes,de-emphasisandextensivepowermanagementfacilities.Thedeviceisavailableinasmall28-pinSSOPpackage.FEATURES•AudioPerformance−97dBSNR(‘A’weighted@48kHz)ADC−100dBSNR(‘A’weighted@48kHz)DAC−1.42–3.6VDigitalSupplyOperation−2.7–3.6VAnalogueSupplyOperation•ADCandDACSamplingFrequency:8kHz–96kHz•SelectableADCHighPassFilter•2or3-WireMPUSerialControlInterface•ProgrammableAudioDataInterfaceModes−I2S,Left,RightJustifiedorDSP−16/20/24/32bitWordLengths−MasterorSlaveClockingMode•StereoAudioInputsandOutputs•MicrophoneInputandElectretBiaswithSideToneMixer•InputandOutputVolumeandMuteControls•HighlyEfficientHeadphoneDriver•PlaybackModePowerConsumption18mW•AnaloguePassThroughPowerConsumption9mW•28-PinSSOPPackageAPPLICATIONS•PortableMP3PlayersandRecorders•CDandMinidiscRecordersBLOCKDIAGRAMMUXMUXVOLVOLADCADCDIGITALFILTERSDIGTALAUDIOINTERFACECONTROLINTERFACEDACDACVOL/MUTEVOL/MUTEH/PDRIVERH/PDRIVERCSBSDINSCLKΣΣRHPOUTLHPOUTROUTLOUTRLINEINLLINEINVMIDDBVDD(3.3V)DGNDAVDDAGND0dB/20dBMICIN+12to-34.5dB,1.5dBStepsCLKOUT+6to-73dB1dBStepsHPVDDHPGND+6to-73dB1dBSteps+12to-34.5dB,1.5dBStepsDCVDD(1.5V)ADCLRCDACLRCBCLKDACDATADCDATOSCXTI/MCLKXTOMODEMICBIASMUTEBypassBypassSideToneSideToneCLKINDIVIDER(Divx1,x2)CLKOUTDIVIDER(Divx1,x2)ATTEN/MUTEMUTEMUTEATTEN/MUTEMUTEMUTEMUTEMUTEMUTEWM8731WM8731AdvancedInformationWOLFSONMICROELECTRONICSLTDAIRev2.0February20012TABLEOFCONTENTSDESCRIPTION.......................................................................................................1FEATURES............................................................................................................1APPLICATIONS.....................................................................................................1BLOCKDIAGRAM.................................................................................................1PINCONFIGURATION..........................................................................................6ORDERINGINFORMATION..................................................................................6PINDESCRIPTION................................................................................................6ABSOLUTEMAXIMUMRATINGS.........................................................................7RECOMMENDEDOPERATINGCONDITIONS.....................................................7ELECTRICALCHARACTERISTICS......................................................................8TERMINOLOGY...................................................................................................10POWERCONSUMPTION....................................................................................11MASTERCLOCKTIMING...................................................................................12DIGITALAUDIOINTERFACE–MASTERMODE13DIGITALAUDIOINTERFACE–SLAVEMODE14MPUINTERFACETIMING15DEVICEDESCRIPTION.......................................................................................17INTRODUCTION17AUDIOSIGNALPATH18LINEINPUTS..........................................................................................................................................18MICROPHONEINPUT............................................................................................................................20MICROPHONEBIAS...............................................................................................................................21ADC.........................................................................................................................................................22ADCFILTERS..............................................................