TheSSM2160andSSM2161allowdigitalcontrolofvolumeofsixandfouraudiochannels,respectively,withamasterlevelcontrolandindividualchannelcontrols.LowdistortionVCAs(VoltageControlledAmplifiers)areusedinthesignalpath.Byusingcontrolledrate-of-changedrivetotheVCAs,the"clicking"associatedwithswitchedresistivenetworksiseliminatedintheMastercontrol.Eachchanneliscontrolledbyadedicated5-bitDACproviding32levelsofgain.Amaster7-bitDACfeedseverycontrolportgiving128levelsofattenuation.Stepsizesarenominally1dBandcanbechangedbyexternalresistors.Channelbalanceismaintainedovertheentiremastercontrolrange.Uponpower-up,alloutputsareautomaticallymuted.Athree-orfour-wireserialdatabusenablesinterfacingwithmostpopularmicrocontrollers.Windows™softwareandanevaluationboardforcontrollingtheSSM2160areavailable.
TheSSM2160canbeoperatedfromsinglesuppliesof+10Vto+20Vordualsuppliesfrom±5Vto±10V.TheSSM2161canbeoperatedfromsinglesuppliesof+8.5Vto+20V(forautomotiveapplications)ordualsuppliesfrom±4.25Vto±10V.Anon-chipreferenceprovidesthecorrectanalogcommonvoltageforsinglesupplyapplications.BothmodelscomeinP-DIPandSOpackages.