电子信息与通信工程专业英语lesson2-2(太原理工大学版).ppt

2020 3 20 可编辑 1 Chapter2CircuitSystemandDesign Outline2 1CircuitandSystem2 2AnalogandDigitalCircuitsDesign2 3RadioReceiverCircuit 2020 3 20 可编辑 2 2 2AnalogandDigitalCircuitsDesign OutlineAnalogcircuitsDigitCircuits 2020 3 20 可编辑 3 Terminology bipolaradj 双极型CMOSabbr ComplementaryMetalOxideSemiconductor互补型金属氧化物半导体semiconductingmaterial半导体材料Integratedcircuits集成电路transistorn 晶体管DCabbr DirectCurrent直流ACabbr AlternateCurrent交流digitaladj 数字的 计数的binaryadj 具有两个的 二进制的 二变量的Booleanalgebra布尔代数positiveadj 确实的 积极的 肯定的 现实的 正的 阳性的 2020 3 20 可编辑 4 negativeadj 否定的 否认的 反面的 消极的反对的 负的 阴极的hexadecimaladj 十六进制的numbersystem计数制CommutativeLaw交换律AssociativeLaw结合律DistributiveLaw分配率invertern 变换器 倒相器 倒换器 反演器 逆变器 非 门truthtablen 真值表combinationaladj 组合的sequentialadj 时序的Flip flopn 触发器 2020 3 20 可编辑 5 Analogcircuitsarecircuitsdealingwithsignalsfreetovaryfromzerotofullpowersupplyvoltage Analogcircuitsareoftenreferredtoaslinearcircuitstoemphasizethevalidcontinuityofsignalrangeforbiddenindigitalcircuits butthislabelisunfortunatelymisleading Introduction Texttour 1 Analogcircuits Moderncircuitdesignisa mixedsignal endeavorthankstotheavailabilityofsophisticatedprocesstechnologiesthatmakeavailablebipolarandCMOS powerandsignal passiveandactivecomponentsonthesamecircuit 2020 3 20 可编辑 6 Justbecauseavoltageorcurrentsignalisallowedtovarysmoothlybetweentheextremesofzeroandfullpowersupplylimitsdoesnotnecessarilymeanthatallmathematicalrelationshipsbetweenthesesignalsarelinearinthe straight line or proportional senseoftheword Manyso called linear circuitsarequitenonlinearintheirbehavior eitherbynecessityofphysicsorbydesign Thisrelativemobilityofelectronswithinamaterialisknownaselectricconductivity Conductivityisdeterminedbythetypesofatomsinamaterial thenumberofprotonsineachatom snucleus determiningitschemicalidentity andhowtheatomsarelinkedtogetherwithoneanother 2020 3 20 可编辑 7 NPNtransistors Infact inthemostbasicandmostcosteffectiveanalogICprocesses thechipdesignerhasatitsdisposaljustthatagoodNPNtransistor 2020 3 20 可编辑 8 Inthiscomponentthecurrentflowentersthecollectorandbaseandexitstheemitter Simplystated thetransistorconductsacollectorcurrentwhichisacopyofthebasecurrentamplifiedbyafactorofbeta Itfollowsthattheemittercurrentisoneplusbetatimesthebasecurrent Atypicalvaluefortheamplificationfactoris100 2020 3 20 可编辑 9 ThePNPtransistoriscomplementarytotheNPN withthecurrentflowenteringtheemitterandexitingthecollectorandbase theoppositeofwhathappensintheNPN SimplicitydictatesthatPNPsareaby productoftheNPNconstruction hencetheyoftenhavelessbetacurrentgainandareslowerthanNPNs PNPtransistors 2020 3 20 可编辑 10 MOStransistors ThedualofBipolarNPNandPNPtransistorsinCMOStechnologyaretheP ChannelandN ChannelMOStransistors Thegeneralfunctionofthetransistorsisthesameindependentlyastheirimplementationbutthereareprosandconstousingbothtechnologies Generallyspeaking thebase theemitter andthecollectorofthebipolartransistorareanalogoustothegate sourceanddrainoftheMOStransistor respectively 2020 3 20 可编辑 11 Thebipolartransistors mainproblem whichisnotpresentinCMOS istheirneedforabasecurrentinordertofunction Suchcurrentisanettransferlossfromemittertocollector Whilethebasecurrentissmallinsmallsignaloperation inpowerapplications wherethetransistorisusedasaswitch thebasecurrentnecessarytokeepthetransistoroncanbeveryhigh 2020 3 20 可编辑 12 Thishighbasecurrentcanleadtoimplementationswithverypoorefficiency Withthepopularityofportableelectronicsandtheneedtoextendbatterylife itisnowonderthatCMOSoftentendstohavetheupperhandoverbipolartechnologies TheadvantageofbipolaroverCMOSthatithasbettertrans conductancegainandbettermatching leadingtobetterdifferentialinputgainstagesandbettervoltagereferences Thebestperformanceprocessesaremixed modeBiCMOS BipolarandCMOS orBCD BipolarCMOSandDMOS processesinwhichthedesignercanusethebestcomponentforthetaskathand 2020 3 20 可编辑 13 2 DigitCircuits BooleanalgebrafundamentalsThephrase Digitalelectronics isusedtodescribethosecircuitsystemswhichprimarilyoperatewiththeuseofonlytwodifferentvoltagelevelsortwootherbinarystates Analogdevicesandsystemsprocesstime varyingsignalsthatcantakeonanyvalueacrossacontinuousrangeofvoltage currentorothermetric Thedifferenceisthatwecanpretendthattheydon t 2020 3 20 可编辑 14 TheNOToperationchangesthevaluetothecomplementofthevalue Thisisalsoreferredtoasinversionornegation TheANDoperationisaBooleanmultiplyandis1onlywhenallvaluesare1 TheANDisliketheoldstringofChristmaslights Allthelightshavetoworktohavethestringylight TheORoperationresultsina1ifanyofthevaluesare1 InBooleanalgebra 1 1 1isvalid Logicallythestatementmeansifthereareoneormoretruevalues theresultistrue 2020 3 20 可编辑 15 CommutativeLaw A B B AAssociativeLawofAddition A B C A B C AssociativeLawofmultiplication A BC AB CDistributiveLaw A B C AB ACIdentity 1 A A 0 A AComplement A A 1 A A 0DeMorgan sTheorem 2020 3 20 可编辑 16 LogicgatesIngeneral agatehasoneormoreinputsandproducesanoutputthatisafunctionofthecurrentinputvalue s Witheachlogicelementthereisa truthtable thatexplainshowtheunitworks Andthereisasymboltorepresenteverygate ThebasicelectronicdigitaloperationsarealsoNOT AND OR buttherearecombinationsofthesethatarealsocommonlyused theNAND NOR andEXCLUSIVENOR 2020 3 20 可编辑 17 CombinationallogicandsequentiallogiccircuitLogiccircuitsareclassifiedintotwotypes combinationalandsequential Acombinationallogicisonewhoseoutputsdependonlyonitscurrentinput Acombinationallogiccircuitmaycontainanarbitrarynumberoflogicgatesandinvertersbutnofeedbackloops asignalpathofacircuitthatallowstheoutputofagatetopropagatebacktotheinputofthatsamegate 2020 3 20 可编辑 18 Whentheinputiscombinedwiththepreviousstateofthelogiccircuits itisreferredtoassequentiallogic Theuseofthepreviousstateiscalledfeedback Theoutputsofsequentiallogiccircuitdependnotonlyonthecurrentinputsbutalsoonthepastsequenceofinputs possiblyarbitrarilyfarbackintime Aseal incircuitisanexampleofasequentiallogiccircuit 2020 3 20 可编辑 19 Intheanalysis uselogicdiagramandproceedtoaformaldescriptionofthefunctionperformedbythatcircuit suchasatruthtableoralogicexpression Inthesynthesis fromaformaldescriptionandproceedingtoalogicdiagram Wehavelearnedthattherearefivepossiblerepresentationsforacombinationallogicfunction 1 truthtable2 analgebraicsumofminterms thecanonicalsum3 amintermlistusingthenotation4 analgebraicproductofmaxterms thecanonicalproduct5amaxtermlistusingthenotation 2020 3 20 可编辑 20 Karnaughmap likeBooleanalgebra isasimplificationtoolapplicabletodigitallogic BooleansimplificationisactuallyfasterthantheKarnaughmapforataskinvolvingtwoorfewerBooleanvariables Itisstillquiteusableatthreevariables butabitslower Atfourinputvariables Booleanalgebrabecomestedious Karnaughmapsarebothfasterandeasier Karnaughmapsworkwellforuptosixinputvariables areusableforuptoeightvariables Formorethansixtoeightvariables simplificationshouldbebyCAD computerautomateddesign Itsimplifiesalogicfunctionbycombiningpairsofadjacent1cellsintoaSum Of Productstermsthatcoversallofthe1cells Formgroupsof1stocoverall0s TheProduct Of Sumssimplifiedresultisbuilt Bythedefinitionofminimalcostsolution theSOPsolutionissimpler 2020 3 20 可编辑 21 Flip flop isthecommonnamegiventotwo statedeviceswhichofferbasicmemoryforsequentiallogicoperations Flip flopsareheavilyusedfordigitaldatastorageandtransferandarecommonlyusedinbankscalled registers forthestorageofbinarynumericaldata Flip Flops 2020 3 20 可编辑 22 2020 3 20 可编辑 23 InanS Rlatch activationoftheSinputsetsthecircuit whileactivationoftheRinputresetsthecircuit IfbothSandRinputsareactivatedsimultaneously thecircuitwillbeinaninvalidcondition TheJ Kflip flopisamodifiedversionofanS Rflip flopwithno invalid or illegal outputstate Soa