Circuit using SR, JK and D Flip-Flop, Working, Truth Table

Truth Table of T flip – flop Home SequentialLogicCircuits DesignofTFlipFlop|CircuitusingSR,JKandDFlip-Flop,Working,TruthTable April27,2021 By RaviTeja Inthistutorial,wewilllearnaboutanotherimportantflip-flopknownastheTFlip-Flop.Wewilllearnitsdesign,workingandalsocoupleofapplicationsofTFlipFlop. Outline IntroductionTFlip–FlopCircuitUsingSRFlip-FlopUsingDFlip-FlopUsingJKFlip-FlopWorkingTruthTableofTflip–flopApplicationsFrequencyDivisionCircuit2-BitParallelLoadRegisterusingTflip–flopsConclusion Introduction Tflip–flopisalsoknownas“ToggleFlip–flop”.Toavoidtheoccurrenceofintermediatestate(alsoknownastheforbiddenstate)inSRflip–flop,weshouldprovideonlyoneinputtotheflip–flopcalledtheTriggerinputorToggleinput(T). Thentheflip–flopactsasaToggleswitch.Togglingmeans‘Changingthenextstateoutputtocomplementofthepresentstateoutput’. WecandesigntheTflip–flopbymakingsimplemodificationstotheJKflip–flop.TheTflip–flopisasingleinputdeviceandhencebyconnectingJandKinputstogetherandgivingthemwithsingleinputcalledT,wecanconvertaJKflip–flopintoTflip–flop. So,aTflip–flopissometimescalledassingleinputJKflip–flop. ThelogicsymbolofTflip–flopisshownbelow.IthasoneToggleinput(T)&oneclocksignalinput(CLK). TFlip–FlopCircuit WecanconstructaTflip–flopbyanyofthefollowingmethods: ConnectingtheoutputfeedbacktotheinputinSRflip–flop. ConnectinganXORwithTinputandQPREVIOUSoutputtotheDatainputinDflip–flop. Hard–wiringtheJandKinputstogetherandconnectingittoTinputinJKflip–flop. UsingSRFlip-Flop WecanconstructaTflip–flopbyconnectingANDgatesasinputtotheNORgateSRlatch.AndoneoftheinputstotheseANDgatesarethefeedbackfromthepresentstateoutputQanditscomplement QtotherespectiveANDgatesi.e.,QtotheANDGateassociatedwithRinputandQtotheANDGateassociatedwithSinput. Atoggleinput(T)isconnectedincommontoboththeANDgatesasaninput.TheANDgatesarealsoconnectedwithcommonClock(CLK)signal. IntheTflip–flop,apulsetrainofnarrowtriggersareprovidedasinput(T)whichwillcausethechangeinoutputstateofflip–flop.So,theseflip–flopsarealsocalledToggleflip–flops.ThecircuitdiagramofaTflip–flopconstructedfromSRlatchisshownbelow.   UsingDFlip-Flop Similarly,aTflip–flopcanbeconstructedbymodifyingDflip–flop.InDflip–flop,theoutputQisXORedwiththeTinputandgivenattheDinput.ThecircuitofaTflip–flopconstructedfromaDflip–flopisshownbelow. UsingJKFlip-Flop ThesimplestoftheconstructionsofaTflip–flopiswithJKflip–flop.TheJinputandKinputoftheJKflip–flopareconnectedtogetherandprovidedwiththeTinput.ThelogiccircuitofaTflip–flopconstructedfromaJKflip–flopisshownbelow. Working Tflip–flopisanedgetriggereddevicei.e.,thelowtohighorhightolowtransitionsontheinputclocksignalwillcauseachangeintheoutputstateoftheflip–flop. TruthTableofTflip–flop ThetruthtableofaTflip–flopisshownbelow. Previous Next T QPREV QPREV QNEXT QNEXT 0 0 1 0 1 0 1 0 1 0 1 0 1 1 0 1 1 0 0 1 Asmentionedearlier,Tflip–flopisanedgetriggereddevice.Forexample,consideraTflip–flopmadeofNANDSRlatchasshownbelow. IftheoutputQ=0,thentheupperNAND(NANDC)isindisablestate(doesn’thaveanydominatinginputs)andlowerNAND(NANDD)gateisinenablecondition(feedbackfromQisthedominatinginput).Thismeans,thetheToggleInputwillsettheinputconditionfortheRSFlip-FlopasR=1andS=0.IfyourecallthetruthtableofRSFlip-Flop,thisconditionwillSETtheoutput.Hence,Qbecomes1. IftheoutputQ=1,thentheupperNANDisinenablestateandlowerNANDgateisindisablecondition.ThisallowstheToggleInputtosettheinputsfortheRSFlip-FlopasR=0andS=1.Thiswillmaketheflip–floptoRESETi.e.,Q=0. Insimpleterms,theoperationoftheTflip–flopis WhentheTinputisLOW,thenthenextsateoftheTflipflopissameasthepresentstate. T=0andpresentstate=0,thenthenextstate=0 T=0andpresentstate=1,thenthenextstate=1 WhentheTinputisHIGHandduringthepositivetransitionoftheclocksignal,thenextstateoftheTflip–flopisthecomplementofthepresentstate. T=1andpresentstate=0,thenthenextstate=1 T=1andpresentstate=1,thenthenextstate=0 AseachincomingtriggeralternatelychangestheSETandRESETinputs,theflip–floptoggles.So,tocompleteonefullcycleofoutputwaveform,itneedtwotriggers.ThismeansthattheTflipflopproducestheoutputatexactlyhalfofthefrequencyofinputfrequency.SoaTflip–flopswillactas“FrequencyDividerCircuit”. ThemaindisadvantageofTflip–flopisthatthestateoftheflip–flopatanappliedtriggerpulseisknownonlywhenthepreviousstateisknown. Generally,TflipflopsarenotavailableasICs.So,theycanbeconstructedbyusingJKflip–flop,SRflip–flopandDflip–flop.ThesymbolofTflip–flopmadefromJKflip–flopisshownbelow. Applications LetusnowseeacoupleofimportantapplicationsofTflip-flop. FrequencyDivisionCircuit 2–BitParallelLoadRegisters FrequencyDivisionCircuit ATflip–flopcanbeusedasa‘FrequencyDividerCircuit’byfeedingbackthecomplementaryoutputQ’totheTinput.ThelogicsymbolofafrequencydividerusingTflip–flopisshownbelow. IftheinputclockfrequencyoftheTflip-flopis‘f’Hz,thenfrequencyofthepulseatoutputQis‘f/2’Hz.Wecancascademanysuchfrequencydividercircuitstofurtherdividethefrequency. 2-BitParallelLoadRegisterusingTflip–flops Weuseregistersandshiftregisterstostorethedata.Butthesizeisalwaysaprimaryconcernformemoryelementssuchasregisters.So,weuse2–bitparallelloadregistersinstead4–bitregisters. Therearetwooperationstobeconsideredwhendesigningaparallelloadregister: HoldtheData ParallelLoadtheData ToholdtheoutputofTflip–flop,simplytheinputTshouldbe0.ButtheParallelLoadisadifficultpart. ParallelLoadmeanstogetthevalueXattheoutputoftheflip–flop.Inordertodothat,weXORtheXinputandpresentstateoutputandgiveitto2to1MUX.TheotherinputtotheMUXisaconstant0(logiclow).TheoutputoftheMUXisconnectedtotheinputoftheTflip–flop. Sinceitisa2–bitregister,twosuchcombinationsareneeded.Thecircuitofa2–bitparallelloadregisterisshownbelow. Conclusion Asimplebeginner’stutorialonTFlip-Flop,whichisalsoknownasToggleFlipFlop.YoulearnedhowtodesignaTflip-flopusingotherflip-flopslikeSRflip-flop,JKflip-flopandDflip-flop,theworkingoftheToggleFlip-Flop,truthtableofTFlip-Flopandalsocoupleofusefulapplications.   RelatedPosts:SRFlipFlop-DesigningusingGatesandApplicationsAstableMultivibratorusing555Timer|Circuit,DutyCycle,…HowToFlipAnImageInGoogleDocsSRAMvsDRAM|Comparison,BasicStructuresandDifferencesDifferentTypesofMemoryonArduino|SRAM,EEPROM,Flash22DifferentTypesofLightSwitches LeaveaReplyCancelreplyYouremailaddresswillnotbepublished.Requiredfieldsaremarked*Comment*Name* Email* Website Δ Menu Learn Tutorials DIY ProductReviews Guides&Howto About