《电子与通信工程专业英语》课件第3章

Unit3IntegratedCircuitNEWWORDSANDPHRASES

NOTES EXERCISES

参考译文

EXTENSIVETEXT

IntegratedCircuitsareusuallycalledICsorchips.Theyarecomplexcircuitswhichhavebeenetchedontotinychipsofsemiconductor(silicon).Thechipispackagedinaplasticholderwithpinsspacedona0.1inch(2.54mm)gridwhichwillfittheholesonbreadboards[1].Veryfinewiresinsidethepackagelinkthechiptothepins.

1．Pinnumbers

Thepinsarenumberedanti-clockwisearoundtheIC(chip)startingnearthenotchordot.Fig3.1showsthenumberingfor8-pinand14-pinICs,buttheprincipleisthesameforallsizes.

Fig3.1Pinnumbers

2．Chipholders(DILsockets)

ICs(chips)areeasilydamagedbyheatwhensolderingandtheirshortpinscannotbeprotectedwithaheatsink.Insteadweuseachipholder,strictlycalledaDILsocket(DIL:DualIn-Line),whichcanbesafelysolderedontothecircuitboard.Thechipispushedintotheholderwhenallsolderingiscomplete.

Chipholdersareonlyneededwhensolderingsotheyarenotusedonbreadboards.

Commerciallyproducedcircuitboardsoftenhavechipssoldereddirectlytotheboardwithoutachipholder,usuallythisisdonebyamachinewhichisabletoworkveryquickly.Pleasedon’tattempttodothisyourselfbecauseyouarelikelytodestroythechipanditwillbedifficulttoremovewithoutdamagebyde-soldering.

Ifyouneedtoremoveachipitcanbegentlyprisedoutoftheholderwithasmallflat-bladescrewdriver.Carefullyleverupeachendbyinsertingthescrewdriverbladebetweenthechipanditsholderandgentlytwistingthescrewdriver.Takecaretostartliftingatbothendsbeforeyouattempttoremovethechip,otherwiseyouwillbendandpossiblybreakthepins.

3．Staticprecautions

ManyICsarestaticsensitiveandcanbedamagedwhenyoutouchthembecauseyourbodymayhavebecomechargedwithstaticelectricity,fromyourclothesforexample.StaticsensitiveICswillbesuppliedinantistaticpackagingwithawarninglabelandtheyshouldbeleftinthispackaginguntilyouarereadytousethem.

ItisusuallyadequatetoearthyourhandsbytouchingametalwaterpipeorwindowframebeforehandlingtheICbutforthemoresensitive(andexpensive)ICsspecialequipmentisavailable,includingearthedwriststrapsandearthedworksurfaces.Youcanmakeanearthedworksurfacewithasheetofaluminiumkitchenfoilandusingacrocodilecliptoconnectthefoiltoametalwaterpipeorwindowframewitha10

k

resistorinseries.

4．Datasheets

DatasheetsareavailableformostICsgivingdetailedinformationabouttheirratingsandfunctions.Insomecasesexamplecircuitsareshown.Thelargeamountofinformationwithsymbolsandabbreviationscanmakedatasheetsseemoverwhelmingtoabeginner,buttheyareworthreadingasyoubecomemoreconfidentbecausetheycontainagreatdealofusefulinformationformoreexperiencedusersdesigningandtestingcircuits.

5．Sinkingandsourcingcurrent

Chipoutputsareoftensaidto“sink”or“source”current.Thetermsrefertothedirectionofthecurrentatthechip’soutput.

Ifthechipissinkingcurrentitisflowingintotheoutput.Thismeansthatadeviceconnectedbetweenthepositivesupply(+Vs)andthechipoutputwillbeswitchedonwhentheoutputislow(0

V).

Ifthechipissourcingcurrentitisflowingoutoftheoutput.Thismeansthatadeviceconnectedbetweenthechipoutputandthenegativesupply(0

V)willbeswitchedonwhentheoutputishigh(+Vs).

Itispossibletoconnecttwodevicestoachipoutputsothatoneisonwhentheoutputislowandtheotherisonwhentheoutputishigh.ThisarrangementisusedintheLevelCrossingprojecttomaketheredLEDsflashalternately.

Themaximumsinkingandsourcingcurrentsforachipoutputareusuallythesamebuttherearesomeexceptions,forexample74LSTTLlogicchipscansinkuptol6

mAbutonlysource2

mA.

6．The555and556timers

The8-pin555timerchipisusedinmanyprojects.apopularversionistheNE555.Mostcircuitswilljustspecify“555timerIC”andtheNE555issuitableforthese.The555output(pin3)cansinkandsourceupto200mA.ThisismorethanmostchipsanditissufficienttosupplyLEDs,relaycoilsandlowcurrentlamps.Toswitchlargercurrentsyoucanconnectatransistor.

The556isadualversionofthe555housedina14-pinpackage.Thetwotimerssharethesamepowersupplypins.

7．LogicICs(chips)

LogicICsprocessdigitalsignalsandtherearemanydevices,includinglogicgates,flip-flops,shiftregisters,countersanddisplaydrivers.Theycanbesplitintotwogroupsaccordingtotheirpinarrangements:the4000seriesandthe74serieswhichconsistsofvariousfamiliessuchasthe74HC,74HCTand74LS.

Formostnewprojectsthe74HCfamilyisthebestchoice.Theolder4000seriesistheonlyfamilywhichworkswithasupplyvoltageofmorethan6

V.The74LSand74HCTfamiliesrequirea5

Vsupplysotheyarenotconvenientforbatteryoperation.

8．PlCmicrocontrollers

APICisaProgrammableIntegratedCircuitmicrocontroller,a“computer-on-a-chip”.TheyhaveaprocessorandmemorytorunaprogramrespondingtoinputsandcontrollingoutputssotheycaneasilyachievecomplexfunctionswhichwouldrequireseveralconventionalICs[2].

ProgrammingaPICmicrocontrollermayseemdauntingtoabeginnerbutthereareanumberofsystemsdesignedtomakethiseasy.ThePICAXEsystemisanexcellentexamplebecauseitusesastandardcomputertoprogram(andre-program)thePICs;nospecialistequipmentisrequiredotherthanalow-costdownloadlead.ProgramscanbewritteninasimpleversionofBASICorusingaflowchart.ThePICAXEprogrammingsoftwareandextensivedocumentationisavailabletodownloadfreeofcharge,makingthesystemidealforeducationandusersathome.

IfyouthinkPICsarenotforyoubecauseyouhaveneverwrittenacomputerprogram,pleaselookatthePICAXEsystem!ItisveryeasytogetstartedusingafewsimpleBASICcommandsandthereareanumberofprojectsavailableaskitswhichareidealforbeginners.

NEWWORDSANDPHRASES

integrate vt. 使结合成为整体

notch n. (边缘或表面上的)V形痕迹，刻痕

vi. 在(事物)上刻V形痕

semiconductor n. 半导体

grid n.格子，格栏；地图上的坐标方格；输电网

anti-clockwise adj. 逆时针方向的

screwdriver n. 螺丝刀；螺丝起子；改锥

antistatic adj. 抗静电的

aluminium n. 铝

beetchedonto n. 被……蚀刻

bepackagedin n. 被……包装

besolderedonto n. 被……焊接

NOTES

[1]Thechipispackagedinaplasticholderwithpinsspacedona0.1inch(2.54mm)gridwhichwillfittheholesonbreadboards.

句中“spacedona0.1inch(2.54mm)grid…”作为后置定语修饰“pins”。“breadboard”为做电路实验时用的面包板，可在上面直接插上元器件和导线组成简单的实验电路。

本句可译为：芯片被封装在带有引脚的塑料插座中，每个引脚间隔0.1英寸(2.54mm)，可插在电路试验板上。

[2]TheyhaveaprocessorandmemorytorunaprogramrespondingtoinputsandcontrollingoutputssotheycaneasilyachievecomplexfunctionswhichwouldrequireseveralconventionalICs.

句中“They”指的是PIC，动名词短语“respondingtoinputs”作为后置定语修饰“aprogram”。

本句可译为：PIC内含一个处理器和存储器，可根据输入来运行程序从而控制输出。因此它们能够很容易地完成一些需多个传统集成电路芯片才能实现的复杂功能。

EXERCISES

I．TranslatethefollowingphrasesintoChinese.

(1)

IntegratedCircuits (2)

DualIn-Line

(3)

sinkcurrent (4)

sourcecurrent

(5)

LevelCrossingproject (6)

flip-flops

(7)

shiftregister (8)

ProgrammableIntegratedCircuit

(9)

computer-on-a-chip

II．TranslatethefollowingparagraphsintoChinese.

(1)

ManyICsarestaticsensitiveandcanbedamagedwhenyoutouchthembecauseyourbodymayhavebecomechargedwithstaticelectricity,fromyourclothesforexample.StaticsensitiveICswillbesuppliedinantistaticpackagingwithawarninglabelandtheyshouldbeleftinthispackaginguntilyouarereadytousethem.

(2)

LogicICsprocessdigitalsignalsandtherearemanydevices,includinglogicgates,flip-flops,shiftregisters,countersanddisplaydrivers.Theycanbesplitintotwogroupsaccordingtotheirpinarrangements:the4000seriesandthe74serieswhichconsistsofvariousfamiliessuchasthe74HC,74HCTand74LS.

参考译文

第三单元集成电路

集成电路通常被称为IC或芯片。它们是被固化在微小的半导体(硅)芯片中的复杂电路。芯片被封装在带有引脚的塑料插座中，每个引脚间隔0.1英寸(2.54

mm)，可插在电路试验板上。在插座下有一些非常精细的导线，(通过它们)将芯片与引脚相连。

1．引脚编号

集成电路芯片的引脚编号从靠近槽口或圆点处开始以逆时针方向排列，图3.1所示为一个8脚和14脚的集成电路芯片。对于其他数量引脚的芯片，编号的规则都是一样的。

2．芯片插座(双列直插式插座)

集成电路芯片很容易被焊接时的热量所损坏，并且它们的短引脚不受散热片保护。因此我们采用芯片座作为替代，严格地说叫双列直插式(DIL，DualIn-Line)插座，它可安全地被焊接到电路板上。当所有的焊接工作完成后，再把芯片嵌入到插座中。

仅在焊接时才使用芯片插座，在电路试验板上是不使用它们的。商业上生产的电路板通常是在没有芯片插座的情况下直接将芯片焊接到电路板上的，通常这项工作都是由运转快速的机械设备完成的。不要试图自己去这样做，因为你很可能会损坏芯片，而且通过拆焊移出芯片时不可避免地会损坏它。

如果需要将芯片移出，可用小平口螺丝刀将它从插座中轻轻地拿出。先将螺丝刀的平口插入芯片和插座，然后轻轻地转动螺丝刀从而将芯片的两端小心地、水平地抬起。在试图将芯片移出前要小心地将芯片的两端抬起，否则会将引脚弄弯或者弄断。

3．静电保护

许多集成电路都对静电敏感，当你接触时可能会损坏它们，因为你的衣服可能让你的身体带静电。静电敏感的集成电路会被放置在带有警告标签的静电保护袋中，不使用时必须把它们放置在袋中。

一般在你接触集成电路前，先将你的手与金属水管或窗框接触，达到接地的效果就足够了。但是对于更为敏感(且昂贵的)的集成电路可利用特殊的装置。这些装置包括接地手环和接地工作台。你可取一块厨房用的铝金属薄片，然后用鳄鱼嘴夹通过串联一个10k

的电阻将它接到金属水管或窗框上，这样就可制成一个接地工作台了。

4．数据手册

大多数的集成电路都附有数据手册，提供产品等级和功能方面的详细信息，有时还给出参考电路。数据手册中大量带有符号和缩写的信息，初学者感到难以理解。但对于有经验的使用者来说，数据手册值得一看，因为它包含了大量的有用信息及设计和测试电路。

5．灌电流和拉电流

芯片的输出通常被称为“灌”或“拉”电流。它们表示了芯片输出端电流的方向。

如果芯片是灌电流式的，那么电流流入输出端。这就意味着在输出端为低电压(0

V)时如果将一个器件连接在正电源和芯片的输出端之间，那么这个器件将会被导通。

如果芯片是拉电流式的，那么电流流出输出端。这就意味着在输出端为高电压(+V)时如果将一个器件连接在负电源和芯片的输出端之间，那么这个器件将会被导通。可以同时将两个器件接到芯片的输出端，其中一个当输出低电压时是通的，另一个当输出高电压时是通的。这种设计方式用于平交路口信号灯项目中用来使红色的发光二极管交替闪烁。

芯片输出的最大拉电流和灌电流通常一样大，但也有些例外，如74LSTTL逻辑芯片能够提供高达16

mA的灌电流，但拉电流只有2

mA。

6．555和556定时器

8脚的555定时器芯片应用于许多项目中，常用的型号为NE555。大多数电路指定使用“555集成电路芯片”，NE555就适用于这种情况。555的输出引脚3的拉电流和灌电流可达200

mA。这比大多数的芯片都大，而且足够驱动发光二极管、继电器线圈和低电流电灯。需产生大电流时，可连接一个晶体管来放大电流。

556是两个555的组合，14脚封装。556内的两个定时器共享一个电源脚。

7．逻辑集成芯片

逻辑集成芯片处理数字信号，这种器件有很多种，包括逻辑门、触发器、移位寄存器、计数器和显示驱动器等。根据它们引脚的排列方式分为两类，即4000系列和74系列，74系列又分为许多子类，如74HC、74HCT和74LS。

对于大多数新的项目，74HC系列是最佳的选择。较早的4000系列是工作电压唯一在6

V以上的系列。74LS和74HCT系列需要5

V电源，因此它们不便于用电池来驱动。

8．可编程集成电路微控制器

PIC就是可编程集成电路微控制器，即一个“片上计算机系统”。PIC内含一个处理器和存储器，可根据输入来运行程序从而控制输出。因此它们能够很容易地完成一些需多个传统集成电路芯片才能实现的复杂功能。

对于初学者来说，可编程集成电路微控制器的编程是非常难的，但是现在有许多使这个过程简化的系统。PICAXE就是一个很好的例子，因为它使用标准的计算机对PIC编程。除了廉价的下载数据线外，它不再需要其他专门的设备。程序可使用简单版本的BASIC编写或使用流程图编写。由于PICAXE编程软件和大量的文件可免费下载，对于教学和家庭用户这个系统是非常理想的。

如果你从未编写过程序，认为PIC不适合你，那么请看PICAXE系统！使用一些简单的BASIC命令很容易入门，并且还有许多对初学者非常理想的案例可作为参考。

EXTENSIVETEXT

HowICProductsAreMade?

TheIntegratedCircuit(IC),atechnologicalwizard,haschangedtheworld,ourlifeandourcivilizationtosuchanextentthatthepresenthumansocietyexistsdirectlyandindirectlyrelyingonICproducts.Themoreadvancedthesocietyis,themoredependentonICitappears.InsomedevelopedcountriessuchastheUnitedStatesandJapan.ICmanufacturinghasbecomeamajorindustryunderlyingthenations’economyNomodemproductcanbemadewithouttheparticipationofICproducts.Therefore,IChasbecomeapillarsupportingourmoderncivilization.

HowisanICproductmade?StudyingtheprocessesinvolvedinICmanufacturingisjustaninterestingsubjectforeveryuniversitystudentmajoringinscienceandtechnology.

Therawmaterialformakingsemiconductorproductsispolycrystallinesilicon,whosepurityisrequiredtobeabove99.9999%.Impurity-freeisessentialtothesuccessofIC-making.Theworkingenvironmentmustbemaintaineddust-freeandoperatorsmustwearoverallslopsanddongloves.Allrawmaterials,solvents,workingmedia，fluidsforflushingintermediateproducts,tools,containersandmachinesmustbefreefromfreemetallicionsandotherimpuritiesthatwouldentertheICproducts.

Thefirststepispreparingsingle-crystallinesiliconsubstrates,duringwhichthepolycrystallinesiliconisfirstcrystallizedintosingle-crystalsiliconrodsinacrystal-pullingfurnace,inwhosevacuumchamberagrainofsiliconcrystalioniskeptturninganddrawnupwardslowly.Fromthesurfaceofthemoltenpolycrystallinesilicon,inseveralhoursofprocessing,arodofsingle-crystallinesiliconwillgrowafterthecrystalLon,inotherwords,itwillcrystallizewiththesamecrystallineasthecrystalLon’s.Thenthesingle-crystallinesiliconrodisslicedonaspecialmachinebyanon-metallicdiskwithdiamondsonitsedge.Thesliceswillbepolishedwithcrystolonpowderuntiltheirsurfacebecomesamirrorlikefine.

Onthesiliconsubstrateanepitomicallayerismade,whereICcomponentsareformedsubsequently.InaCVD(chemicalvapordeposition)process,thesiliconsubstratesplacedinavacuumcrystaltubearefirstheatedto1,600℃byhigh-frequencyradiopowerandthenSiH2C12andcertaingaseouscompoundsofAs(arsenic)orP(phosphorus)isinjectedintothetubetomakeadepositofseveralurnontheirsurface.IonsofAsorPareimpuritydeliberatelyaddedtothesingle-crystallinesiliconstructuretosupplyelectronsthattransmit“negative”currentinthesiliconcrystals,whichiscalledn-typesilicon.B(boron)canbeaddedasimpuritytoproducep-typesiliconthatsuppliesholesfortransmitting“positive”current.Whetherap-typeorann-typesiliconsubstrateisneededdependsonwhattypeoftransistorsisexpectedtobemanufacturedonit:n-p-ntypeorp-n-ptype.

Anotherpreparationismakingaseriesofmasksonwhichmicrocircuitpatternsaredescribed.Eachmaskisusedto“print”,thespecificmicrocircuitpatternontothesiliconsubstrateinaprocessknownasthephotolithography.Thesizeofeachmaskisbigenoughtocoverthesiliconslice.Usually,theyaremadeofcellulosefilmormetalfilm.

Tomakethosemasks,firstacircuitpatternisdesignedtodescribethephysicalstructureofthecircuitunit,whichmayconsistdozensoftransistorsandresistorsaswellasconnectingwires.Eachbipolar-typetransistorhasanemitter,acollectorandabase,andaMOStransistorhasthreeelectrodes:source,drainandgate,allmadeinasinglewaferofsilicon.Resistorscanbemadeinalmostthesamewayastransistors.Then,takingintoaccounttheprocessinwhichthestructureofthosetransistorscanbeproduced,aseriesofpatternsformakingasinglecircuitunitonthesubstratecanbedrawneitherbyhandorbyacomputer-aidedgraphicsplotter.Thesepatternsareminiaturedusingspecialcamerashavinghighresolvingpower.Further,eachpatternisduplicatedusingalaser-positioningcameratoproduceanarrayofthesamepatternonafilms,onwhicheachelementofthatarrayhasexactlythesamepatternandtheyseparatefromeachotherwithexactlythesamedistance,inotherwords,theyarealignedonrowsandcolumnswithhighprecision.Precisionoftheirrelativepositiononthefilmisofparticularimportancebecausethemaskssomadewithmanypatternsoneachcanguaranteeprecisepinpointingofallpatternsonthesiliconsubstrateduringthephoto-lithographprocess.Finally,thefilmisfurtherminimized.

ThephotolithographyprocesswillberepeatedlyinvolvedinmakingICproducts,withtheprocessas:

(1)

Onthefilmtobeprocessed,phenolnovolacsystemresinandphoto-resistareappliedinuniformthickness.

(2)

Photo-maskengravedwithdesiredcircuitpatternsisplacedonthephoto-resistlayerforexposuretolight;thepartoftheresistexposedtolightisphoto-decomposed.

(3)

Whenthesubstrateissoakedinalkalineliquid,thosepartswhichhavephoto-decomposedarewashedaway,leavingapatternontheresistlayer.

(4)

Theoriginalfilmtobeprocessedbyetchingusingphoto-resistasamaskisremovedfromthepatternarea.

(5)

Whentheresistmaskisremoved,theoriginalfilmtobeprocessedremainsasthatcontainingcircuitpatterns.

ThefollowingdescriptionprovidesyouwithknowledgeofthesimplifiedprocessesinvolvedinmakingaMOStransistor.Actually,alltransistorsonasinglesiliconsubstratearemadesimultaneouslyduringthoseprocesses.

(1)

Amirror-polishedsingle-crystalsiliconsubstratesurfaceisheatedto900to1,000℃inanoxidationatmosphereforoxidationofthesurface,sothatanapproximately0.005-μm-thickSiO2filmisgenerated.LaminatingtheSiO2film,Si3N4filmisdepositedbyaCVDprocessinwhichSiH2C12(dichloridesilane)andNH2(ammonium)reactat700to800℃toforma0.1-

m-thickfilmontheareawherethetransistorismanufactured.Therestoftheareaiscalledelementseparationdomain,whichhorizontallyseparatestransistordomainsfromeachother.

(2)Thesubstrateisexposedagaininahigh-temperatureoxidationatmospherefortheseparationareatobeselectivelyoxidizedtoform1-

m-thickoxidefilms.Si3N4filmactsasamasktodeterminetheboundaryseparatingthetransistordomainfromtheseparationarea.

(3)

RemainingSi3N4filmandsiliconoxidefilmundertheSi3N4areremoved.Next,0.02to0.03-

m-thickgateoxidefilmisdepositedonthesurfaceofthesiliconsubstrateinthetransistordomainbyathermaloxidationprocess.

(4)

ACVDprocessbywhichsilane(Si3N4)isdecomposedat650℃isappliedfordepositing0.3to0.5-μm-thickpolycrystallinesiliconontheentiresurfaceofthedomain.Crystallizedpolycrystallinesiliconshowshighresistancecharacteristicsasitis,soAsorPisaddedasimpuritytosupplyelectronsascarriersofnegativecurrentinsiliconcrystals.Foraddingimpurity,theimpurityisionizedtoformanionbeam,whichisthenacceleratedbyanelectricfieldinvacuumandinjectedbyanioninjectionprocess.Finally,SiO2filmisprocessedintothepatternofagateelectrode.

(5)

Atstage(4),ofasioninjectionprocess,asionsreachthesiliconsurfaceunderthethingateoxidefilmtogeneratesourceanddrainelectrodes.Inthiscases,AsionsonlyreachareasofthesourceanddrainelectrodedomainbecausetheyarehinderedfromreachingthesiliconsurfacebythickSiO2filmcoveringallbutthetransistordomain.

Stages(1)to(5)formthebasicprocessbywhichaMOStransistorismanufactured.Whenalargenumberoftransistorsinacircuitunitareconnectedbyaluminumwiringinaspecificarea,manufacturingofanICproductiscompleted,exceptthefollowingadditionalprocess.

(6)

Toseparatetheelectrodesoftransistorsfromthewiringlayers,aninsulationlayerisdeposited.ThematerialsaresiliconoxideandPSG(phospho-silicateglass)obtainedbyapplicationofaCVDprocessusingsilaneandoxygenaddedwithphosphine(PH3),PSGshowsliquidityat1,000℃toformsmoothsurface.

(7)

ContactholeswhichreachthesurfaceofbothsourceanddrainelectrodesaremadethroughthePSGlayer.

(8)

Finally,a1-

m-thickaluminumlayerisdepositedovertheentireareatomakewiringwithPVD(physicalvapordeposition)methodssuchassputtering.

ThefollowingtopicsareofparticularsignificanceinICmanufacturing.

AnobvioustrendinICmanufacturingistheever-increasingintegrationoftransistorsinanICproduct.WhenthenumberoftransistorsintegratedinanICproductexceeds100k,theproductiscalledlarge-scaleintegrated(LSI)circuit.ThelargerthecapacityofanLSIproductthehigheritscost-effect.

ThequalifierrateofanLSIproductisanessentialfactorthatdetermineswhetherthatproductcansu