电子元器件应用-Advanced Bus Interface Logic Selection Gui

SLLAdvancedBusInterfaceLogicProductsSelectionGuideandReferenceTHEWORLDLEADERINDSPANDANALOGTexasInstrumentsIncorporated1SLLAdvancedBusInterfaceLogicProductsSelectionGuideandReferenceContentsPageBusInterfaceSolutionsOverviewIntroduction...........................................................2AdvancedBusInterfaceLogic.............................................4EnhancedTransceiverLogic(ETL)..........................................5BackplaneTransceiverLogic(SN74FBxxx)....................................7GunningTransceiverLogic(SN74GTLxxx)....................................7GunningTransceiverLogicPlus(SN74GTLPxxx)...............................8CombinedApplications.................................................10ProductSelectionGuide(ABT,ABTE/ETL,ALVT,FB+/BTL,FCT,GTL,GTLPandLVT).....11AppendixAForMoreInformation...................................................20ApplicationReportsSummary.............................................20TIWorldwideTechnicalSupport.............................................23FormoreinformationaboutAdvancedBusInterfaceProducts,visit(slewrate)canbeslowerandstillallowhighertransmissionrates.Differentialcomplementarysignalscanceloutcommon-modenoisethatimprovessignalquality.ForDifferentialorBalancedTransmission,apairofcablesortracesisnecessaryforeachchannel.Ononeline,a“true”signalistransmitted,whileonthesecondone,theinvertedsignalistransmitted.Thereceiverdetectsbasicallythedifferenceininputsandvoltageswitchestheoutputdependingonwhichinputlineismorepositivethantheotherone.Duetothecommon-moderejectioncapabilityofadifferentialamplifierthisnoisewillberejected.Additionally,anyexternalnoiseiscoupledontobothlinesasacommon-modevoltageandisrejectedbythereceivers.Single-EndedTransmissionisperformedononesignallineandtheoutputisinterpretedwithrespecttoground.Theadvantagesofsingle-endedtransmissionaresimplicityandlowcostofimplementation.Sinceasingle-endedBusInterfaceSolutionsOverviewIntroductionIntoday’sinformation-hungrysociety,transmittingdataoverseveralinchesbetweencomputermemoryanddisplayscreenisjustascriticalassendingithalfwayaroundtheglobeonfiberoptics.TexasInstruments(TI)isconstantlypushingthecapabilitiesandextendingtheperformanceparametersofpracticallyeverydatatransmissionstandard,includingRS-232,RS-423,RS-422,RS-485,FibreChannel,VME,LVDS(lowvoltagedifferentialsignaling),IEEE1394(Firewire),USB(UniversalSerialBus),GeoPort,IrDA(InfraredDataAssociation),BTLandGTL.Overthepast3years,TISLLhascombineditsexpertiseinhigh-speeddigitalandanalogtechnologiestooffernewsingle-endedbackplaneoptimizedtransceivers,whichprovidehigherdataratesindistributedloadstoallowtier2usesanalter-nativetomorecomplexandcostlydifferentialsolutions.Withinadatatransmissionsystem,therearenumerouswaysofconnectingthetransmitters,receivers,boardsandbackplanes.Figure1showshowcardsareconnectedinatypicalequipmentcabinet.Insomesituations,itisneces-sarytoconnectindividualcardstogetherwithhighdatathroughputpointtopointconnectionsbutmostequip-mentracksincludemulticardbackplaneswherecontrolordatasignalsaresharedviabackplaneboardtraces.Thisselectionguidefeaturesthebestsingle-endedsolutionsthatprovidetier2usersexcellentsignalintegrityacrosstheirmulticardbackplanes.Datatransmissionisthecatch-allphraseformovingdatafromonelocationtoanotherandtwoparametersareimportant—thedistancebetweenthesendingandreceivingCard-to-cardconnection:Point-to-pointusingLVDS,SERDES(TLK2501,etc.)Cabinet-to-cabinetconnection:•Backplane-to-backplanewithSERDES(TLK2500,etc.)•Card-to-cardwithSERDES(TLK2501,etc.)Card-to-cardconnection:Overbackplanemultipoint-to-multipointusingGTLP,FB+orVMEsingle-endedorLVDMdifferentialRack-to-rackconnection:Point-to-pointusingLVDSorPECLFigure1.SolutionsforSystemConnectionsTexasInstrumentsIncorporated3BusInterfaceSolutionsOverviewSLLAdvancedBusInterfaceLogicProductssystemrequiresonlyonelinepersignal,whiledifferentialsignalsrequiretwo,itisidealforparallelcommunicationwheremanylinesarerequired,e.g.,PC,parallelprinterportorserialcommunicationwithmanyhandshakinglines,e.g.,EIA-232attier3levelsandonVMEorproprietarybackplanesattier2levels.Finally,single-endeddevicestransferdatabutalsooffervariouslogicfunctionslikeflip-flopsandregistersinadditiontotrans-ceiversthatcomeinsmall,mediumandlargebitwidths.Mostdifferentialdevicesonlysendorreceivedata.Themaindisadvantageofthesingle-endedsolutionisi