TheAD1939isahighperformance,single-chipcodecthatprovidesfouranalog-to-digitalconverters(ADCs)withdifferentialinput,andeightdigital-to-analogconverters(DACs)withdifferentialoutputusingtheAnalogDevices,Inc.patentedmultibitsigma-delta(Σ-Δ)architecture.AnSPIportisincluded,allowingamicrocontrollertoadjustvolumeandmanyotherparameters.TheAD1939operatesfrom3.3Vdigitalandanalogsupplies.TheAD1939isavailableina64-lead(differentialoutput)LQFPpackage.
TheAD1939isdesignedforlowEMI.Thisconsiderationisapparentinboththesystemandcircuitdesignarchitectures.Byusingtheon-boardPLLtoderivethemasterclockfromtheLRclockorfromanexternalcrystal,theAD1939eliminatestheneedforaseparatehighfrequencymasterclockandcanalsobeusedwithasuppressedbitclock.TheDACsandADCsaredesignedusingthelatestAnalogDevicescontinuoustimearchitecturestofurtherminimizeEMI.Byusing3.3Vsupplies,powerconsumptionisminimized,furtherreducingemissions.