T Is for Toggle: Understanding the T Flip-Flop

The “T” in “T flip-flop” stands for “toggle.” When you toggle a light switch, you are changing from one state (on or off) to the other state ... NetworkSites: Latest News TechnicalArticles Latest Projects Education Latest News TechnicalArticles MarketInsights Education LogIn Join Login JoinAAC Orsigninwith Facebook Google LinkedIn GitHub     0:00 / 0:00 Podcast Latest Subscribe Google Spotify Apple iHeartRadio Stitcher Pandora TuneIn Menu Articles Latest News Projects TechnicalArticles IndustryArticles IndustryWhitePapers Forums Latest HardwareDesign Embedded&Programming Education Math&Science Community Education Textbooks VideoLectures&Tutorials Worksheets IndustryWebinars VirtualWorkshops Tools Calculators PartSearch TestEquipmentDatabase BomTool ICDesignCenter Videos Latest NewProducts VideoTutorials On-DemandWebinars TechChats VirtualWorkshops Datasheets Giveaways Industry Tech Days Podcast Connectwithus NetworkSites: TechnicalArticle TIsforToggle:UnderstandingtheTFlip-Flop JoinourEngineeringCommunity!Sign-inwith: 4 Home TechnicalArticles TIsforToggle:UnderstandingtheTFlip-Flop TechnicalArticle TIsforToggle:UnderstandingtheTFlip-Flop April17,2018byRobertKeim Thistechbriefprovidesanoverviewofasomewhatuncommonmemberoftheflip-flopfamily. Thistechbriefprovidesanoverviewofasomewhatuncommonmemberoftheflip-flopfamily.RelatedInformation Edge-triggeredLatches:Flip-Flops Flip-flopsarefundamentalcomponentsintheworldofdigitalelectronics.Thesedevicesareusedasclockdividersandone-bitstorageelements,andbyconnectingmultipleflip-flopsintherightwayyoucanmakeshiftregisters,storageregisters,andcounters.Unlikemerelogicgates,flip-flopsutilizefeedbacktocreatecircuits(calledsequentiallogic,asopposedtocombinationallogic)inwhichthefuturestateisinfluencedbythepreviousstate. Ifyouwanttomakeaflip-flop,youstartwithagatedlatch,suchasthegatedSRlatch:     Agatedlatchisausefulcomponent,buttheoutputcanchangewhenevertheenablesignalishigh.Thisintroducesalackofprecisionandreliabilityintowhateverdigitalinterfaceisbuiltaroundthelatch.Itwouldbebetterifthelatchwouldrespondtoinputchangesonlyataspecificmomentintime.Thetroubleis,oncewehaveimplementedthisfunctionality,thelatchisnolongeralatch.It’saflip-flop.   AnSRflip-flop.   Thepulsetransitiondetector(PTD)convertsarisingorfallingedgeintoashortpulse.Thispulsebecomestheenablesignal,suchthatthelatchisenabledonlyforashortperiodoftimefollowingthetransition.Thelatch-plus-PTDarrangementiswhatwecallaflip-flop,andsincewe’reusuallyworkingwithlogiccircuitsthataregovernedbyclocksignals,theflip-flop’senablesignalisoftenreferredtoassimplytheclock.   TheTFlip-Flop Theessentialcharacteristicofaflip-flopisthatitchangesitsoutputstateinresponsetoapositiveornegativetransitiononthecontrolsignal.Butthereismoretoaflip-flopthanthis:wealsohavetodefinetheinput-to-outputrelationship.Thisiswhytherearedifferenttypesofflip-flops;theyareallsensitivetoclockedges,buttheyperformdifferentactionsinresponsetotheinputstates. The“T”in“Tflip-flop”standsfor“toggle.”Whenyoutogglealightswitch,youarechangingfromonestate(onoroff)totheotherstate(offoron).Thisisequivalenttowhathappenswhenyouprovidealogic-highinputtoaTflip-flop:iftheoutputiscurrentlylogichigh,itchangestologiclow;ifit’scurrentlylogiclow,itchangestologichigh.Alogic-lowinputcausestheTflip-floptomaintainitscurrentoutputstate. Hereisthesameinformationintruth-tableform:     FromSRorJKtoT Youcanmodifytheinput-to-outputrelationshipofanexistingflip-flopbyaddinglogicgatesandappropriateinterconnections.AACalreadyhasanabundanceofinformationonthistopic;ifyouwanttoexplorethedetails,ourarticleonthe conversionofflip-flops isagoodplacetostart.Inthisshortarticle,I’llsimplypresenttwowaystocreateaTflip-flopfromanexistingflip-flop. IfyouhaveanSRflip-flop,allyouneedistwoANDgatestoturnitintoaTflip-flop:     Theprocessiseveneasierifyou’restartingwithaJKflip-flop.Noadditionalgatesarerequired;allyouneedtodoisconnectthesameinputsignaltobothinputpins:       Tflip-flopsarehandywhenyouneedtoreducethefrequencyofaclocksignal:IfyoukeeptheTinputatlogichighandusetheoriginalclocksignalastheflip-flopclock,theoutputwillchangestateonceperclockperiod(assumingthattheflip-flopisnotsensitivetobothclockedges).Thus,theoutputclockwillbehalfthefrequencyoftheinputclock.IfyouknowofacleveruseforaTflip-flop,letusknowinthecomments. RelatedContent ModernDevelopmentforControlAutomation BuildingtinyMLSolutionsfortheEdge StandardPowerCapacitorsforDCLinkDesignedforAdvancedSemiconductorDemands&MarketTrends GateDriverSolutionsforFastSwitchingApplications ConvertMCDtoLumens LearnMoreAbout: tflip-flop digitaldesign flip-flop digitallatch sequentiallogic Comments 4Comments Logintocomment B BhavaniChekuri June01,2019 canuexplainaboutasynchronousactivelowTflip-flop Like. Reply M Mandeep321 July02,2019 Consider'S'asanactive-low,asynchronousinput. Dependingupontheoutputtheyproduce,Tflip-flopscanbeofTwotypesinbehaviour(usuallymanufacturerdependent) Type1.whenS=0,output=1--Herewecallthemthat'S'has'set'theoutputwhenasserted. Type2.whenS=0,output=0--Herewecallthemthat'S'has'reset'theoutputwhenasserted. Usually,itismentionedthatwhatanasynchronousinputwoulddouponassertion.Ifnothingismentioned,youcanchooseeithertypeandmentionitatthebeginningofyoursolution. Like. Reply F free-bee June29,2020 AcleverusageforaT-typeflipflop?IhaveacircuitdesignthatusesaDPSTswitchtocontrolsystempower.Issueis,thecircuititselfresidesonaPCB.Includethepartwhereithasbatterybackup,IhavesixindividualconnectionsthatareexternaltothePCB.IrecentlyfoundanIC(FPF1320)thatImightbeabletousetoreplacetheswitch(it’sactuallytoreplaceanotherpart).Itwasdesignedtocontrolsystempowerusinganenablepin.IfIcanutilizeaTflipflopAndcleverlymanipulatemypowerrails,Icanaddabutton(withdebouncing)andgetridoftheswitch.Then,myPCBwillonlyhavetwoexternalconnections(battery+and-).Myonlyproblem—howIendeduponthispage—isthatIaminneedofaTflipflop. Butanyway,there’sonecreativeuseforaflipflop:controllingsystempower. Like. Reply Kurs June06,2022 CanuexplainaboutTflipflopwithenable Like. 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