Rail-to-Rail: Railroading and the Electronics of Op Amps

Abstract:Railroadshavehadrail-to-railcomponentsforyearsthatwere,infact,nearlyrailtorail.Opampsemploythesamenearlyrail-to-railtradition.Thisapplicationnotediscussesrail-to-railopamps,andexplainswhysomeinputsandoutputscanbelessthan,nearly,orslightlymorethanthepowerrails.Maxim>AppNotes>AmplifierandComparatorCircuitsKeywords:railtorail,opamps,input,output,signalswings,beyondtherails,MOS,bi-polar,CMOS,Pinputpair,Ncommon-mode,supplySep28,2009bias,currentchanges,signmagnitude,crossover,distortion,NPN,PNP,impedance,matchphase,reversal,latchup,overdriveAPPLICATIONNOTE4428Rail-to-Rail:RailroadingandtheElectronicsofOpAmpsBy:BillLaumeister,StrategicApplicationsEngineerAbstract:Railroadshavehadrail-to-railcomponentsforyearsthatwere,infact,nearlyrailtorail.Opampsemploythesamenearlyrail-to-railtradition.Thisapplicationnotediscussesrail-to-railopamps,andexplainswhysomeinputsandoutputscanbelessthan,nearly,orslightlymorethanthepowerrails.IntroductionF