模拟电子技术基础（西安邮电大学）智慧树知到期末考试答案章节答案2024年西安邮电大学

模拟电子技术基础（西安邮电大学）智慧树知到期末考试答案+章节答案2024年西安邮电大学TheoutputimpedanceofaBJTamplifiertendstobemuchlessthanthatofacomparableFETamplifier.（

）

答案:错

答案:low-passfilterWhichtransistoramplifierconfigurationisthemostcommonlyused?

（

）

答案:common-emitter

答案:fixed-biasconfigurationforan

n-channelJFET

答案:

答案:Whendesigningavoltage-dividerbiascircuit,thedividerresistors（

）.

答案:determinethebasevoltageasthedropacrossbase-commonresistor###shouldcarrycurrentsthatare10timesthebasecurrent###shouldcarryapproximatelyequalcurrent

答案:Typicaldifferentialamplifiercircuitchangesfromdouble-endedinputtosingle-endedinput,common-modevoltagegain

（

）.

答案:unchangedWhenap-njunctionisreverse-biased,thedepletionlayeris________andthedeviceactsasanear-perfect________（

）.

答案:widened;insulatorIftheresistorbypasscapacitorinthesourcelegisremoved,thevoltagegainofthesmallsignalFETamplifier(

).

答案:willdecreaseAgainof7isrequiredfromanoninvertingconstant-multiplierop-ampcircuit.Iftheinputresistoris5kΩ,whatshouldbethevalueofthefeedbackresistor?

（

）

答案:30kΩTheCMRRofaninvertingamplifieralwayslowerthanthatofitsop-ampbecause（

）.

答案:thevalueofdifferentialgainforaninvertingamplifierislowerthanthatofitsop-ampTheop-ampcircuitthathasacapacitorasthefeedbackcomponentiscalleda(n)___B___.

答案:integrator

答案:differentiatorDependingontheconfigurationoftheamplifier,themagnitudeoftheno-loadcurrentgainforasingleBJTtransistoramplifiertypicallyrangesfrom（

）.

答案:justalittlelessthan1toalevelthatmayexceedonehundredVoltage-seriesfeedback（

）

theinputimpedanceofanop-amp.

答案:increasesDependingontheconfigurationoftheamplifier,themagnitudeoftheno-loadvoltagegainforasingleBJTtransistoramplifiertypicallyrangesfrom（

）.

答案:justalittlelessthan1toafewhundredWhyisthearrowontheBJTschematicsymbolimportant?（

）

答案:ItidentifiestheemitterterminalandthetypeofBJT.Transistorcircuitsthatarequitestableandrelativelyinsensitivetotemperaturevariationshave（

）.

答案:largebetas

答案:Inmostcases,whichtwoofthethreeBJTterminalcurrentsareapproximatelyequalinvalue?（

）

答案:emittercurrentandbasecurrent

答案:

答案:saturationregionWhenatransistorisinsaturation,thetotalcollectorcurrentislimitedby（

）.

答案:collectorsupplyvoltageandthetotalresistanceinthecollectorandemittercircuitsThe（

）

terminaloftheJFFTistheequivalentofthecollectorterminalofaBJT.

答案:drainTheoutputimpedanceofaBJTis（

）.

答案:resistiveCalculatethegainofanegativefeedbackamplifierhavingA=1000andF=0.099.（

）

答案:10Howmanyfeedbackresistorsarefoundina3-inputvoltagesummingcircuitthatisconstructedaroundanop-amp?

（

）

答案:1Theinputpowertoadeviceis5000Wat400V.Theoutputpowerofthedeviceis750W,andtheoutputimpedanceis25Ω.Calculatethevoltagegainindecibels.（

）

答案:-9.311dB

答案:0Negativecurrentfeedback（

）.

答案:

答案:remainsthesameCMOSstandsfor（

）.

答案:complementaryMOS

答案:

答案:0.904mATheanalysisthatwemostlyworkwithisthatofthen-channeldevice.Forp-channeldevicesthetransfercurveemployedisthe________imageandthedefinedcurrentdirectionsare________.

（

）

答案:mirror;reversedAp-njunctionisforwardbiasedwhen（

）.

答案:theappliedpotentialcausesthe

n-typematerialtobemorenegativethanthe

p-typematerial

答案:

答案:20.2μA

答案:inputimpedance

答案:120MOSFETstypicallyhaveaninputimpedancevaluethatis（

）.

答案:higherthantheJFETAnop-ampbandpassactivefilterprovidesaconstantoutput（

）.

答案:

答案:voltagebufferTheidealdiodesymbolhasanarrowthatpointsinthedirectionof（

）.

答案:theforwardcurrentflowThereversesaturationcurrentofadiodewilljustabout（

）forevery10°Criseinthediodetemperature.

答案:doubleInaself-biascircuitforann-channelJFETtransistorthese1f-biasline（

）.

答案:isslantedandpassesthroughoriginWhenaBJTisincutoff,thecollector-to-emittervoltageistypicallyequalto（

）.

答案:collectorsupplyvoltageVoltage-seriesfeedback（

）

theoutputimpedanceofanop-amp.

答案:decreasesThevoltagegainofaFETamplifierisgenerallylargerthanthatofacomparableBJTamplifier.（

）

答案:错Electronsaretheminoritycarriersinann-typematerial.（

）

答案:错Acharacteristicofvoltagedivider-biasinFETcircuitsis（

）.

答案:Whichtypeofop-ampcircuithasunitygain,nophaseinversion,highinputimpedance,andlowoutputimpedance?

（

）

答案:voltagebufferWhyisdesignforaspecificbiaspointdesirableformostamplifiers?

（

）

答案:Itallowsoptimumdcoperationofthecircuit.###Itallowsoptimumacoperationofthecircuit.###Tomeetmanufacturersuggestedopeningpoint.Theapproximationthatallowssuperpositiontobeusedtoisolatetheacanalysisandthedcanalysisofsmall-signalamplifiersisthatthecircuitresponseis（

）.

答案:linearWhichofthefollowingisanadvantageofusingdBrepresentationsofgainvalues?（

）

答案:Inmultistageamplifiers,gaincalculationsaresimplifiedbytheuseofdBvalues.###PositiveandnegativedBvaluesrepresentgainandlossvaluesthatarereciprocalsofeachother.###Usingdbvalues,wecanrepresentlargegainvalueswithrelativelysmallnumbers.Theactofgivingofflightbyapplyinganelectricalsourceofenergyiscalled(

).

答案:electroluminescenceAsthedevicetemperatureincreases,semiconductormaterialstendtohave

（

）.

答案:anincreasingnumberoffreeelectronsImpedancematchingisimportantfor（

）.

答案:maximumpowertransferfromsourcetoloadAnamplifierhasanoutputpowerof500W.WhatisthevalueofthepowergainindBforthecircuit?（

）

答案:CannotbedeterminedfromtheinformationgivenTwoofthefactorsassociatedwithbiasstabilityare（

）.

答案:theβandthejunctiontemperature

答案:0.000125AclassDamplifier（

）.

答案:worksonlywithdigitalandpulsedwaveforms

答案:npn-typeBJT

答案:

答案:1:1Whichofthefollowingarepropertiesoflogarithms'?（

）

答案:

答案:89.0μAWhenusingvoltagedivider-biasinFETamplifiers,increasingthesizeofthesourceresistorresultsin（

）.

答案:lowerquiescentvaluesThecommonmoderejectionratio(CMRR)istheratioof（

）.

答案:thedifferencemodegaintothecommonmodegainAp-njunctionisreversebiasedwhen

（

）.

答案:theappliedpotentialcausesthe

n-typematerialtobemorepositivethanthe

p-typematerial

答案:Thebase-emitterjunctionisforward-biasedandthecollector-basejunctionisreversed-biased.AmajordisadvantageofMOSFETsis（

）.

答案:thatitissensitivetoelectrostaticdischargesThe（

）

terminaloftheJFETistheequivalentofthebaseterminalofaBJT.

答案:gateWhenaBJTisbiasedinthecut-offregion,itsbase-emitterjunctionis________-biasedanditscollector-basejunctionis________-biased.（

）

答案:reverse;reverseThetransitioncapacitanceofadiodeisashuntcapacitiveeffectthatoccurswhenthediode（

）.

答案:isreverse-biasedClassDamplifiershaveamaximumtheoreticalefficiencyof（

）.

答案:over90%Theinputimpedanceofavoltage-shuntfeedbackamplifier（

）

theinputimpedanceofitsop-amp.

答案:isdecreasedwhencomparedtoTheinputimpedanceofacommon-baseBJTconfigurationistypically(

).

答案:lessthan50ΩWhentestedwithanohmmeter,adiodeshouldhavearelativelyhighresistancefor(

)

condition.

答案:thereverse-biasedAclassAamplifierhasan8VPPoutputthatisbeingappliedtoa200Ωload.Whatisthetotalacloadpower?

（

）

答案:40mWForatwo-portsystem,likeaBJTamplifier,theno-loadvoltagegain（

）.

答案:isalwaysgreaterthantheloadedvoltagegainThe（

）

diodeisashortcircuitfortheregionofconductionanditisanopencircuitintheregionofnonconduction.

答案:idealForagate-to-drainvoltagelessthanthethresholdlevelthedraincurrentofanenhancement-typeMOSFETis（

）.

答案:100mA（

）biasingmaybeusedwithD-MOSFETsbutnotwithJFETs.

答案:ZeroA（

）

isacombinationofcircuitelements,properlychosen,thatbestapproximatetheactualbehaviorofasemiconductordeviceunderspecificoperatingconditions.

答案:model

答案:voltagefeedbackratioIftheresistorintheemitterlegisnotbypassedbyacapacitorthenthevoltagegainofthesmallsignalamplifierwill（

）.

答案:decreaseIntheintegratedoperationalamplifiercircuit,the

（

）

couplingmodeisadoptedbetweenthecircuitofalllevels.

答案:directWhichofthefollowingexpressionsistrue?（

）

答案:ThetwoinputvoltagesofthedifferentialamplifierareUi1=0.04V,andUi2=0.08V,thecommonmodeinputvoltage

（

）.

答案:0.06V

答案:Iftheresistorintheemitterlegisnotbypassedbyacapacitorthentheinputimpedanceofthesmallsignalamplifierwill（

）.

答案:increaseIncreasingthetemperatureofaforward-biaseddiode

（

）.

答案:causesforwardcurrenttoincreaseA(n)（

）

isaddedtothefixed-biasconfigurationtoimprovebiasstability.

答案:emitterresistorAsthechannelwidthofaJFETdecreases,thesource-to-drainresistance（

）.

答案:increasesAmplifieracinputandoutputcurrentsare（

）.

答案:alwaysinphaseIfonesilicondiodeandonegermaniumdiodeareconnectedinseries,thevoltagedropacrossthecombinationofthetwodiodeswillbeequalto(

).

答案:theforwarddropequaltothatofthesumofthevoltagedropsacrossthetwodiodes

答案:30mV

答案:voltageshuntfeedback

答案:hasaverypositiveThe（

）

terminaloftheJFEI'istheequivalentoftheemitterterminalofaBJT.

答案:source

答案:+2.5VoltsTheroll-offrateofasecondorderfilteris（

）.

答案:40dB/decadeor12dB/octaveTheinputimpedanceofacommon-emitterconfigurationistypically(

).

答案:between300Ωand10kΩTherearetransistorsthatarecalledswitchingtransistorsbecause（

）.

答案:ofthespeedatwhichtheycanbechangedfromontooffThecommon-emitter,forward-current,amplificationfactorisbetterknownas（

）.

答案:acβ

答案:invertingconstant-gainmultiplier

答案:596.55μAAddinganegativevoltage-feedbacknetworktoanamplifierhasnoeffectonthevalueof（

）forthecircuit.

答案:frequencyresponse###signaldistortion###inputimpedanceThegainindecibelsofapowergainof10,000,000is（

）.

答案:70dBTheinputcurrentforaFETamplifierisgenerallyassumedtobezero.（

）

答案:对

答案:282kΩTheinputresistanceofastabilizedfixed-biascircuitconfigurationis（

）.

答案:directlyrelatedtotheemitterresistorWhichofthefollowingstatementsistrue?（

）

答案:Op-ampshaveextremelyhighinputimpedance.###Op-ampsarehigh-gaindcamplifiers###Op-ampshaveextremelylowoutputimpedance.Theadvantageofnegativefeedbackis（

）.

答案:voltagegainthatismorestable###loweroutputimpedance###higherinputimpedanceAnop-amphigh-passactivefilterprovidesaconstantoutput（

）.

答案:

答案:20.0kΩTheinputimpedanceofaFETamplifiertendstobemuchgreaterthanacomparableBJTamplifier.（

）

答案:对Pentavalentatomsareoftenreferredtoas(

).

答案:donoratoms

答案:6.68mA

答案:IntheZenerregionthecurrent________andthevoltageacrossthediode（

）.

答案:canincreasealot;isalmostconstantClassCamplifiersareusedmostlyin（

）

circuits.

答案:tuned

答案:125and1.450kΩWhentestedwithanohmmeter,adiodeshouldhavearelativelysmallresistancefor(

)condition.

答案:theforward-biased

答案:bandpassfilter

答案:outputadmittance

答案:16.97mAduringthenegativehalfcycleCurrent-seriesfeedback（

）

theinputimpedanceofanop-amp.

答案:increasesAmplifieracinputandoutputvoltagesare（

）.

答案:inphaseinallbutoneamplifierconfigurationWhenaBJThasitsbase-emitterjunctionforwardbiasedanditscollector-basejunctionreversebiased,itisbiasedinthe（

）.

答案:activeregion

答案:80Thepointofintersectionbetweenthecharacteristiccurveofthediodeandtheresistorsloadlineisknownasthe(

).

答案:All

oftheseWhichofthefollowingbiasingcombinationsisnotnormallyassociatedwithoneofthethreetransistoroperatingregions?（

）

答案:E-Bjunction=reverse,C-Bjunction=forwardTypicaldifferentialamplifiercircuitchangesfromdouble-endedoutputtosingle-endedoutput,common-modevoltagegain（

）.

答案:increase

答案:110.3

答案:0.133Negativevoltagefeedback（

）.

答案:

答案:2000ΩThesimplestbiasingarrangementforthen-channelJFETis（

）.

答案:fixedbiasTypicaldifferentialamplifiercircuitchangesfromdouble-endedinputtosingle-endedinput,differential-modevoltagegain（

）

.

答案:unchangedInafixed-biascircuitforann-channelJFETtransistorthebiasline（

）.

答案:Thedepletion-typeMOSFET'hasspecificationsandmanycharacteristicsthataresimilartothe（

）.

答案:JFET

答案:veryhighinputimpedanceandveryhighvoltagegain

答案:positivelogicORgate

答案:1.6mAThevoltagefollowertypicallyhasavoltagegainvalueof（

）.

答案:1

答案:ManyMOSFETdevicesnowcontaininternal（

）

thatprotectthesedevicesfromstaticelectricity.

答案:back-to-backzenerdiodesThepower-handlinglevelsofaMOSFET（

）.

答案:isusuallylessthan1WTheelectrodewithn-typematerialofadiodeiscalledthe(

).

答案:cathodeApopulararrangementforenhancementtypeMOSFETbiasingis（

）.

答案:drain-feedbackbiasingTheinputimpedanceforacommon-emitterconfigurationcanbeexpressedas(

).

答案:ThemaximumpossibleefficiencyofaclassAamplifierisequalto（

）.

答案:25%Silicondiodeshavebeenmoresignificantlydevelopedthangermaniumbecause

(

).

答案:itischeaper

答案:1.5V

答案:AclassBpush-pullamplifier（

）.

答案:conductsbetween180°and360°degreesoftheinputwaveform,dependingontheamountofdcbiasTheop-ampcircuitthataddeachinputandmultipliesthesumbyafixedamountiscalleda(n)（

）.

答案:summingamplifier

答案:lessthanorequalto

答案:Thelow-frequencyresponseofaBJTamplifierisaffectedby（

）.

答案:thecouplingandbypasscapacitorvalues

答案:-0.8VInthecut-offregion,thebase-emitterjunction（

）.

答案:andthebase-collectorjunctionsarebothreverse-biasedInthedesignofanemitter-biasstabilizedcircuitengineering,judgmentmustbeusedbecausethe（

）.

答案:NotatallTheJFETisa（

）.

答案:voltage-controlleddeviceTheoutputofanop-ampvoltagebufferischaracterizedby（

）.

答案:

答案:

答案:18VCurrent-seriesfeedback（

）theoutputimpedanceofanop-amp.

答案:hasnoeffecton

答案:1=collector,2=emitter,3=base

答案:0V

答案:1.33mWhattwoparametersrepresenttheFETtransfercharacteristic?（

）

答案:gate-to-sourcevoltageanddraincurrent

答案:1.5V

答案:subtractorWithtransformercouplingthemaximumtheoreticalefficiencyofaclassAamplifiercanbeincreasedupto（

）.

答案:50%WhenaBJTtransistorisusedinaswitchingcircuit,itoperatesinthe（

）.

答案:saturationandcutoffregions

答案:Thebase-10logarithmof100,000is（

）.

答案:5

答案:exactlyequalto

答案:

答案:fromthecollectorterminaltotheemitterterminalInasmall-signaltransistor,thetypicalrangeoftheparameterαis（

）.

答案:almostequalto1butalwayslessthan1(0.9to1.0)Theself-biasconfigurationdevelopsthecontrollinggate-to-sourcevoltageacrossaresistorintroducedinthe（

）.

答案:sourceleg

答案:undefinedThelevelofdrain-to-sourcevoltagewherethetwodepletionsregionsappeartotouchisknownas（

）.

答案:pinch-off

答案:zero(about0.3Volts)Theoutputimpedanceofcurrent-shuntfeedbackamplifier（

）

theoutputimpedanceofitsop-amp.

答案:isincreasedwhencomparedtoCalculatethevoltagegainforvoltageseriesfeedbackwhentheamplifiergainisA=-2000andF=-1/50.

（

）

答案:-48.78Anamplifierhasagain-bandwidthproductof200MHz.Afeedbacknetworkisaddedthathasafeedbackfactor(1+βA)of18.88.Whatisthegain-bandwidthproductforthecircuitwiththeaddedfeedbacknetwork?（

）

答案:200MHz

答案:voltageseriesfeedback

答案:inputimpedancewithfeedback410kΩAclassBamplifier(notpush-pull)（

）.

答案:conductsthrough180°oftheinputwaveformThepowerthatanamplifierdeliverstoaloadisequaltothedifferencebetweenthepowerthatthecircuitdrawsfromthepowersupplyandthepowerthatthecircuitdissipates.（

）

答案:对ThemaximumtheoreticalefficiencyofanRC-coupledclassAamplifieris（

）.

答案:25%CrossoverdistortioninclassBamplifiersispreventedby（

）.

答案:biasingthetransistorsslightlyabovecutoffPoweramplifiersaretypicallyusedtodrivelowimpedanceloads.（

）

答案:对

答案:

答案:20.0kΩ

答案:high-passfilterAsummingintegratorisanop-ampintegratorthathas（

）.

答案:multipleinputresistorsandfeedbackcapacitorsAsecondorderlow-passfilterhasahigh-endroll-offof（

）.

答案:40dB/decadeThebandwidthofanamplifieris（

）.

答案:Whenagivenop-amphasacommon-modeinputof10V,theoutputofthedeviceis10V.

Whenthedevicehasadifferentialinputof2mV,theoutputofthedeviceis10V.WhatistheCMPRofthedevice?（

）

答案:5000:1Theoperationalamplifierwillonlyslightlyamplifysignals（

）.

答案:thatarecommononboththeinputsTheinvertingandnoninvertinginputstoanop-ampareusedtodrivea(n)（

）

amplifier.

答案:differential

答案:40NegativedBvaluesrepresent（

）.

答案:powerlossesA3-dBdropinβoccursat（

）.

答案:Anamplifierhasamidbandpowergainof24,500.WhatisthevalueofthepowergainindBforthecircuit?（

）

答案:43.9dB

答案:Ifseveralidenticalstagesofamplifiers,eachhavingtheexactsameupperandlowercutofffrequencies,areconnectedincascade,thenthebandwidthoftheresultingamplifierwill（

）.

答案:decreaseThe（

）

FETamplifierhaslowinputimpedance,highoutputimpedance,andhighvoltagegain.

答案:common-gate

答案:

答案:The（

）

amplifierhashighinputimpedance,lowoutputimpedance,andlowvoltagegain.

答案:common-drainTheFETversionoftheBJT'scommon-emitterconfigurationisthe（

）

circuit.

答案:common-sourceGenerally,itisgooddesignpracticeforlinearamplifierstohaveoperatingpointsthatcloseto（

）.

答案:themidpointoftheloadlineWhichofthefollowingbiasingcircuitscanbeusedwithE-MOSFETs?

（

）

答案:drain-feedbackbias

答案:selfbiasforan

n-channelJFETTheprimarydifferencebetweenJFETsanddepletion-typeMOSFETsis（

）.

答案:AJFETcanbebiasedinseveraldifferentways.Thecommonmethod(s)ofbiasingann-channelJFETis(are)（

）.

答案:self-biasconfiguration###voltage-dividerbiasconfiguration###fixed-biasconfigurationTheregionoftheJFETdraincurvethatliesbetweenpinch-offandbreakdowniscalled（

）.

答案:thesaturationregionFETsusually（

）.

答案:haveahigherinputimpudencethanBJTs###aresmallerinconstructionthanBJTs###arelesssensitivetotemperaturechangethanBJTs

答案:10.28mAShockley'sequationdefinesthe（

）

oftheFETandareunaffectedbythenetworkinwhichthedeviceisemployed.

答案:transfercharacteristicsInthefamilyofFETs,