NAND and NOR Gate as Universal Gates - Electrical4U

A universal gate is a logic gate which can implement any Boolean function without the need to use any other type of logic gate. SkiptocontentMenuNovember1,2020February24,2012byElectrical4UContentsWhatareUniversalGates?NANDGateAsAUniversalGateNORGateAsAUniversalGateWhatareUniversalGates?AuniversalgateisalogicgatewhichcanimplementanyBooleanfunctionwithouttheneedtouseanyothertypeoflogicgate.TheNORgateandNANDgateareuniversalgates.ThismeansthatyoucancreateanylogicalBooleanexpressionusingonlyNORgatesoronlyNANDgates.Inpractice,thisisadvantageoussinceNORandNANDgatesareeconomicalandeasiertofabricatethanotherlogicgates.SomuchsothatanANDgateistypicallyimplementedasaNANDgatefollowedbyaninverter(nottheotherwayaround)!Similarly,anORgateistypicallyrealisedasaNORgatefollowedbyaninverter.Otherlogicalgates–suchasANDgates,NOTgatesandORgates–donothavethispropertyofuniversality.NotethatcombinedthesethreelogicgatescanimplementallofthepossibleBooleanswitchingfunctions,butnotindividually.HenceunliketheNORandNANDlogicgates,theyarenotclassifiedasuniversalgates.Ifyouwhichtoplayaroundwiththeseuniversalgatesaspartofanelectronicsproject,manyofthebestArduinostarterkitscontaintheseuniversalNORandNANDgates.NowwewilllookattheoperationofNORgatesandNANDgatesasuniversalgates.NANDGateAsAUniversalGateThebelowdiagramisofatwo-inputNANDgate.ThefirstpartisanANDgateandthesecondpartisadotafteritrepresentsaNOTgate.DuringtheoperationoftheNANDgate,theinputsarefirstgoingthroughANDgateandafterthat,theoutputgetsreversed,andwegetthefinaloutput.NowwewilllookatthetruthtableofNANDgate.WewillconsiderthetruthtableoftheaboveNANDgatei.e.atwo-inputNANDgate.ThetwoinputsareAandB.Nowwewillseehowthisgatecanbeusedtomakeothergates.ThisisthecircuitdiagramofaNANDgateusedtomakeworklikeaNOTgate,theoriginallogicgatediagramofNOTgateisgivenbesidesthecircuitdiagrambelow.TheabovediagramisofanORgatemadefromcombinationsofNANDgates,arrangedinapropermanner.ThetruthtableofanORgateisalsogivenbesidethediagram.NowwewillseethedesignofanANDgatefromNANDgates.TheabovediagramisofanANDgatemadefromNANDgate.SowecanseethatallthethreebasicgatescanbemadebyonlyusingNANDgates,that’swhythisgateiscalledUniversalGate,anditisappropriate.NORGateAsAUniversalGateWehaveseenhowtheNANDgatecanbeusedtomakeallthethreebasicgatesbyusingthatalone.NowwewilldiscussthesameincaseofNORgate.TheabovediagramisofanORgatemadebyonlyusingNORgates.TheoutputofthisgateisexactlysimilartothatofasingleORgate.WecanseethecircuitarrangementofORgateusing,NORgateissimilartothatofANDgateusingNANDgates.TheabovediagramasthenamesuggestsisofANDgateusingonlyNORgate,againwecanseethatthecircuitdiagramofANDgateusingonlyNORgateisexactlysimilartothatofORgateusingonlyNANDgates.NowwewillfinallyseehowwecanmakeaNOTgatebyusingonlyNORgates.TheabovediagramisofaNOTgatemadebyusingaNORgate.ThecircuitdiagramissimilartothatofNOTgatemadebyusingonlyNANDgate.So,fromtheabovediscussion,itisclearthatallthethreebasicgates(AND,OR,NOT)canbemadebyonlyusingNORgate.Andthus,itcanbeaptlytermedasUniversalGate.WantToLearnFaster?🎓Getelectricalarticlesdeliveredtoyourinboxeveryweek.Nocreditcardrequired—it’s100%free.AboutElectrical4UElectrical4Uisdedicatedtotheteachingandsharingofallthingsrelatedtoelectricalandelectronicsengineering....RelatedArticlesNANDGate:Whatisit?(Working…DigitalLogicGatesINHIBITGateFanOutofLogicGatesLeaveaCommentCancelreplyCommentNameEmailΔRecentPostsreportthisadPleasefeelfreetocontactusifyou’dliketorequestaspecifictopic.Clickheretoseeourprivacypolicy.WeareaparticipantintheAmazonServicesLLCAssociatesProgram,anaffiliateadvertisingprogramdesignedtoprovideameansforustoearnfeesbylinkingtoAmazon.comandaffiliatedsites.Fulldisclaimerhere.xx