Digitally-Controlled Phase Shift Using the DS1669
Abstract:Thisapplicationbriefdescribeshowtocontrolanalogphaseshiftdigitallyusingacombinationofdigitalpotentiometersandstandardoperationalamplifiers(opamps).Itisintendedtoserveasadesignexampleforengineersneedingtoimplementdigitalphaseshiftinacircuitrywithnospecificapplication.Itpresentscommonopampphaseshiftconfigurationsandhowtoimplementthemusingadigitalpotentiometerinplaceofmechanicalpotentiometersorfixedresistors.Formulasforcalculatingphaseshiftareincludedintheapplicationnote.ApplicationNote184Digitally-ControlledPhaseShiftUsingtheDS1669www.maxim-ic.comCONTROLLINGPHASESHIFTDIGITALLYAlteringthephaseresponseofasignalwithoutchangingitsamplitudecharacteristicsiscommonlyperformedusinganallpassfilter,asinFigure1.TheresponseofthiscircuitisgivenbyAsimplephaseshiftcircuitcanbeimplementedusinganallpassfilter.Figure1AsthesignalfrequencyvariesfromDCtoinfinity,thephaseshiftwillvaryfrom0to+180degrees.YoucanalsoseethatbyvaryingR1,thephaseshiftatagivenfrequ
