1、山东信息职业技术学院电子工程系UnitTwoAnalogCircuit山东信息职业技术学院电子工程系NewWordsandExpressionsdiodedaiud二极管nonlinearnnlini非线性one-way 单向的valvevlv阀门semiconductorsemikndkt半导体schematicski:mtik原理图symbolsimbl图表arrows箭头batterybtri电源lamplmp灯permitpmit准许prohibitpruhibit禁止polaritypulrti极性Conversely相反switchswit开关oddlydli 奇怪地invent发
2、明山东信息职业技术学院电子工程系predominantly占主导地位的conventional knvennl 习惯的、传统的notationnutein符号、标记metallurgicallymell:dikli冶金siliconsilikn硅n-typeN型p-typeP型juxtaposeddkstpuzd 紧靠的ohmmeterummi:t欧姆表qualitativelykwlittivli 定性地purpose 目的expect期望militarymilitri军用civiliansiviljn民用peakpi:k峰值clamperklmp钳子rectification整流photi
3、cfutik光decorationdekrein装潢、装饰山东信息职业技术学院电子工程系TextDiodeAdiodeisanonlinearelectricaldeviceallowingcurrenttomovethroughitinonedirectionwithfargreatereasethanintheotherandusuallyactingasaone-wayvalveforcurrent.Themostcommonkindofdiodeinmoderncircuitdesignisthesemiconductordiode,althoughotherdiodetechnolo
4、giesexist.SemiconductordiodesaresymbolizedinschematicdiagramssuchasFig.2-1.InFig.2-1,arrowsindicatethedirectionofelectroncurrentflow.山东信息职业技术学院电子工程系Whenplacedinasimplebattery-lampcircuit,thediodewilleitheralloworpreventcurrentthroughthelamp,dependingonthepolarityoftheappliedvoltage.(Fig.2-2)(a)Curre
5、ntflowispermitted;thediodeisforwardbiased.(b)Currentflowisprohibited;thediodeisreversedbiased.山东信息职业技术学院电子工程系Whenthepolarityofthebatteryissuchthatelectronsareallowedtoflowthroughthediode,thediodeissaidtobeforward-biased.Conversely,whenthebatteryis“backward”andthediodeblockscurrent,thediodeissaidtobe
6、reverse-biased.Adiodemaybethoughtofaslikeaswitch:“closed”whenforward-biasedand“open”whenreverse-biased.Oddlyenough,thedirectionofthediodesymbols“arrowhead”pointsagainstthedirectionofelectronflow.Thisisbecausethediodesymbolwasinventedbyengineers,whopredominantlyuseconventionalflownotationintheirschem
7、atics,showingcurrentasaflowofchargefromthepositive(+)sideofthevoltagesourcetothenegative(-).Thisconventionholdstrueforallsemiconductorsymbolspossessing“arrowheads”.Thearrowpointsinthepermitteddirectionofconventionalflow,andagainstthepermitteddirectionofelectronflow.oddlyenough：稀奇的是：稀奇的是holdstruefor：
8、适用于：适用于山东信息职业技术学院电子工程系Onewaytomakeasemiconductordiodeistometallurgicallycreateawaferofsiliconcontainingn-typematerialadjoiningp-typematerial.Inann-channelMOSFET,forexample,then-typedrainjuxtaposedtothep-typechannelregionformsadiode.Anohmmetermaybeusedtoqualitativelycheckdiodefunction.Thereshouldbelo
9、wresistancemeasuredonewayandveryhighresistancemeasuredtheotherway.Whenusinganohmmeterforthispurpose,besureyouknowwhichtestleadispositiveandwhichisnegative!Theactualpolaritymaynotfollowthecolorsoftheleadsasyoumightexpect,dependingontheparticulardesignofmeter.山东信息职业技术学院电子工程系Thediodeispopularlyappliedi
10、nelectricequipmentwhetherformilitaryuseorcivilianuse.Forexample:peakdetector,clampercircuits,voltagemultipliersandrectificationwhichisthemostpopularapplicationofthediode.AndnowLED（LightEmittingDiode),atypeofdiodewhichcanbedirectlychangetheelectricsignalintothephoticsignal,ispopularlyusedforlighting,
11、display,signalanddecorationinourdailylife.山东信息职业技术学院电子工程系Exercises:Trytomatchthefollowingcolumns:1.MOSFET正向偏置2.schematicdiagrams施加电压3.forward-biased 高电阻4.reverse-biased电压倍增器5.LED原理图6.voltagemultipliers反向偏置7.highresistance发光二极管8.appliedvoltage金属氧化物半导体场效管山东信息职业技术学院电子工程系PassageBNewWordsandExpressionstr
12、ansistortrnsist三极管amplifiermplifai放大器response反应accuracykjursi精确，准确digital 半导体analog原理图regulationrejulein 图表oscillatorssileitz振荡器package包装，封装individuallyindividjuli分别地，独立地integrated集成的billion十亿，数以十亿计的，大量fundamentalfndmentl基本的，必要的govern统治，控制山东信息职业技术学院电子工程系cellularseljul利用电台网通讯的，蜂窝式无线通讯系统的categorieskti
13、riz类别bipolarbaipul有两极的，双极的；两极世界的junction dkn 结点，会合点solid-state使用电晶体的，不用真空管的，researchers 研究人员laboratorieslbrtriz实验室consists包含，包括sandwichsnwid把夹在之间emitterimit发射极collector集电极base基极elementelimnt原理，特性conducting传导condition状态holes空穴attract吸引山东信息职业技术学院电子工程系operationprein工作，运行opposite相反的connecting链接common共有的
14、公共的electrodeilektrud电极configurationknfijurein 构造，接法wired连线，以线加强consumeknsju:m消耗terminals端子draindrein漏极channel沟道conductivitykndktiviti导电性potentialputenl电压，电势山东信息职业技术学院电子工程系PassageBTransistorThetransistorisanonlinearsemiconductordevicebeingsimilartothediode,commonlyusedasanamplifieroranelectricallyco
15、ntrolledswitch.Becauseofitsfastresponseandaccuracy,thetransistormaybeusedinawidevarietyofdigitalandanalogfunctions,includingamplification,switching,voltageregulation,signalmodulation,andoscillators.Transistorsmaybepackagedindividuallyoraspartofanintegratedcircuit,whichmayholdabillionormoretransistor
16、sinaverysmallarea.Sothetransistorisbecomingthefundamentalbuildingblockofthecircuitrythatgovernstheoperationofcomputers,cellularphones,andallothermodernelectronics.山东信息职业技术学院电子工程系Therearetwomajortransistorcategories:ThebipolartransistorAlsocalled“thebipolarjunctiontransistor”(BJT)andthefieldeffecttra
17、nsistor(FET).Thefirsttypeofsolid-stateelectronictransistorwasmadebyresearchersWilliamShockley,JohnBardeenandWalterBrattainatBellLaboratoriesinDecember1947.And“BipolarJunctionTransistor”wasinventedbyWilliamShocklyin1950whichisthecommonstanderofthecurrenttransistor.山东信息职业技术学院电子工程系Thebipolarjunctiontra
18、nsistorconsistsofthreeregionsofsemiconductormaterial.Onetypeiscalledan-p-ntransistor,inwhichtworegionsofn-typematerialsandwichaverythinlayerofp-typematerial.Thetwon-typematerialregionsofthen-p-ntransistorarecalledtheemitterandcollectorandthep-typematerialiscalledthebase.n-p-ntransistorsaresymbolized
19、inschematicdiagramssuchasFig2-3.山东信息职业技术学院电子工程系Whenusedasanamplifyingelement,thebasetoemitterjunctionisinaforward-biased(conducting)condition,andthebasetocollectorjunctionisreverse-biasedornon-conducting.Smallchangesinthebasetoemittercurrent(theinputsignal)causeeitherholes(forpnpdevices)orfreeelectr
20、ons(fornpn)toenterthebasefromtheemitter.Theattractingvoltageofthecollectorcausesthemajorityofthesechargestocrossintoandbecollectedbythecollector,resultinginamplification.山东信息职业技术学院电子工程系Theonlyfunctionaldifferencebetweenap-n-ptransistorandann-p-ntransistoristheproperbiasing(polarity)ofthejunctionswhe
21、noperating.Foranygivenstateofoperation,thecurrentdirectionsandvoltagepolaritiesforeachtypeoftransistorareexactlyoppositeeachother.Therearethreewaysofconnectingatransistor,dependingontheusetowhichitisbeingput.Thewaysareclassifiedbytheelectrodethatiscommontoboththeinputandtheoutput.Theyarecalled:(a)co
22、mmon-baseconfiguration(b)common-emitterconfiguration(c)common-collectorconfiguration山东信息职业技术学院电子工程系Althoughthefirsttransistorsandfirstsiliconchipsusedbipolartransistors,mostchipstodayareFET(fieldeffecttransistors)wiredasCMOSlogic,whichconsumelesspower.AFEThasthreeterminals，asource,adrainandagate.The
23、semiconductorregionbetweensourceanddrainiscalledachannelanditsconductivityiscontrolledbythepotentialofthegateterminal.山东信息职业技术学院电子工程系Exercises:Trytomatchthefollowingcolumns:1.signalmodulation模拟电路2.analogfunctions信号调制3.cellularphones 双极型晶体管4.BJT共基极5.FET手机、移动电话6.crossinto场效应晶体管7.properbiasing共集电极mon-b
24、ase 穿过mon-emitter正确偏置mon-collector共发射极山东信息职业技术学院电子工程系ReadingAmplifierMuchasthegateabstractionformsthefoundationofmostofdigitalelectronics,theoperationalamplifierformsthebasisformuchofelectroniccircuitdesign.Theoperationalamplifierisarguablythemostusefulsingledeviceinanalogelectroniccircuitry.Withonl
25、yahandfulofexternalcomponents,itcanbemadetoperformawidevarietyofanalogsignalprocessingtasks.Itisalsoquiteaffordable,mostgeneral-purposeamplifierssellingforunderadollarapiece.Moderndesignshavebeenengineeredwithdurabilityinmindaswell:severalop-ampsaremanufacturedthatcansustaindirectshort-circuitsonthe
26、iroutputswithoutdamage.山东信息职业技术学院电子工程系Thenameoperationalamplifieroriginatesfromthebygonedaysoftheanalogcomputer(1940-1960),inwhichtheconstantsindifferentialequationswererepresentedbythegainsofamplifiers.Thustheseamplifiers,constructedfrombalancedpairsofspeciallymanufacturedvacuumtubes,hadtohaverelia
27、ble,known,fixedgains.Becausetransistorsareinherentlymoretemperature-dependentthanvacuumtubes,itwasatfirstthoughtthatsatisfactorytransistorOpAmpscouldnotbebuilt.Butin1964,itwasdiscoveredthatbyfabricatingbalancedtransistorpairsclosetogetheronasinglesiliconchiptominimizethermalgradients,thetemperaturep
28、roblemscouldbeovercome.Andthuswereborninrapidsuccessionthe703,the709,andthentheubiquitous741.OpAmpsarerarelyusedforanalogcomputersnow,butinsteadhavebecomeuniversalbuildingblocksinallaspectsofanalogcircuitry.山东信息职业技术学院电子工程系TheOpAmpisamultistagetwo-inputdifferentialamplifierthatisdesignedtobeanalmosti
29、dealcontroldevice,specifically,avoltage-controlledvoltagesource.AnabstractrepresentationoftheoperationalamplifiershowninFig2-4suggestsitisafour-portdevice.Thefourportsareaninputport,anoutputport,andapairofpowerports.A+VS-voltage(forexample,15volts)isappliedatthepluspowerportandaVS-voltage(forexample
30、15volts)isappliedattheminuspowerport.Aninputvoltage(thecontrol)appliedacrossthenon-invertingandinvertinginputterminalsoftheOpAmpisamplifiedbyalargeamountandappearsattheoutputport.Intheoperationalamplifierabstraction,theinputimpedanceacrosstheinputportisinfinity,andtheoutputimpedanceiszero.Thegain,o
31、rthefactorbywhichtheinputvoltageisamplified,isalsoinfinity.山东信息职业技术学院电子工程系ThesymbolandstandardlabelingfortheoperationalamplifierareshowninFig2-4(a).Thetworequiredexternalpowersupplieshavebeenexplicitlyshowninthediagram,althoughshowingthemisnottheusualpractice.Allfivecurrentshavebeenlabeled,inadditio
32、ntoappropriatenodevoltages,referredtotheindicatedcommongroundterminal.Inthisprimitivecircuit,thevoltageviisusedtocontroltheoutputvoltagevo.Letusexaminethiscontrolfunctionindetailtofindoutboththeextentofthecontrol,andthecostofthecontrol;thatis,howmuchpowermustbeappliedfromsourcevitocontrolagivenamoun
33、tofpoweratthevoterminal.Toaddressthefirstproblem,wesetupthecircuitexactlyasinFig2-5(a),andmeasuretheoutputvoltagevo,bothasafunctionoftimeandasafunctionofvi,assumingviissomelow-frequencysinusoid.TheresultsareshowninFig2-5(b)and2-5(c).Notethedifferenceinscaleofthevoltageaxes,indicatingthattheoutputvol
34、tageisperhaps300,000timesaslargeastheinputvoltage.Theplotofvoversusvishowsaregionaroundtheoriginwherevoisfairlylinearlyrelatedtovi,butmuchbeyondthisrangethecontrolbecomesineffective,andvostaysatafixedvoltage,orsaturates,atroughlyeither+12voltsor12volts,dependingonthepolarityofvi.Thecurveswillalsodif
35、ferfordifferentsamplesofthesameOpAmptype.山东信息职业技术学院电子工程系Differentdevicesofthesametypemighthavedifferentcharacteristics.Thecharacteristicsmightalsodependontemperature.Onekeytotheusefulnessoftheselittlecircuitsisintheengineeringprincipleoffeedback,particularlynegativefeedback,inwhichaportionoftheoutpu
36、tsignaloftheOpAmpisfedbacktothevinputoftheOpAmp.Anditconstitutesthefoundationofalmostallautomaticcontrolprocesses.ExamplesofOpAmpcircuitsbuiltthiswayincludeinvertingandnon-invertingamplifiers,buffers,adders,integrators,anddifferentiators.OpAmpcircuitsaresometimesbuiltusingthepositivefeedbackconnecti
37、on,inwhichaportionoftheoutputsignaloftheOpAmpisfedbacktothev+inputoftheOpAmp.ExamplesofsuchOpAmpcircuitsincludeoscillatorsandcomparators.山东信息职业技术学院电子工程系Homework翻译Apracticalenergysourcemaytakeoneofmanyforms,forexample,dependingonelectrochemical,electromagnetic,thermoelectricandphotoelectricetc.,inpri
38、nciple,butforthepurposeofcircuitanalysisonlytwoidealizedformsarerecognized,tooneofwhichallpracticalsourcesapproximate.Therearethevoltagesourceandthecurrentsource.Thevoltagesourcemaintainsaconstantterminalvoltageirrespectiveofthecurrentsuppliedtotheload.Itisimportanttoappreciatethatthevoltagemaybeafu
39、nctionof,forexample,time,temperature,pressureetc.Itisconstantonlywithrespecttovariationsofload.Thecurrentsourcemaintainsaconstantcurrentintheloadirrespectiveoftheterminalvoltagewhich,inthiscase,isdeterminedbythemagnitudeoftheload.Aswiththevoltagesource,thegeneratedcurrentmaydependonmanyotherfactors,butitsoneessentialattributesisitsindependenceofload.
