模电英文课件ch3.1PPT推荐.ppt
- 文档编号:7172692
- 上传时间:2023-05-08
- 格式:PPT
- 页数:26
- 大小:899.50KB
模电英文课件ch3.1PPT推荐.ppt
《模电英文课件ch3.1PPT推荐.ppt》由会员分享,可在线阅读,更多相关《模电英文课件ch3.1PPT推荐.ppt(26页珍藏版)》请在冰点文库上搜索。
NPNandPNP.,B-Ejunction,B-Cjunction,Baseterminal,Emitterterminal,Collectorterminal,Emitter,Collector,Base,Symbol,3.1.1TransistorStructure,Featureoftransistorstructure,(3)Basemustbeverynarrow.,
(1)Impuritydopingconcentrationinemitterregionismuchlargerthanothertworegions.,
(2)Areaofcollectorregionisbiggerthanthatofemitter.,3.1.2NPNTransistor:
Forward-ActiveModeOperation,Amplificationcondition,Itiscalledtheforward-activeoperatingmode,oractiveregion.,1.Transferprocessofcarriersinnpn,
(1)Emitterregionemitelectronsintobase.,
(2)Collectorregioncollectelectronsinjectedbasefromemitter.,(3)B-Evoltagecontrolscollectorcurrent.,Iftransistorisusedasanamplifyingdevice.,B-Ejunctionisforwardbiased.B-Cjunctionisreversebiased.,NPNbipolartransistorbiasedintheforward-activemode,3.1.2NPNTransistor:
Forward-ActiveModeOperation,1.Transferprocessofcarriers,3.1.2NPNTransistor:
Forward-ActiveModeOperation,Therearetwotypesofcarriers,electronsandholescontributingtothecurrent,sothetransistoriscalledbipolarjunctiontransistor(BJT).,EmitterCurrent,VT_thermalvoltage,IES_emitterleakagecurrent,2.Currentrelationships,IE=IB+IC,IC=InC+ICBO,IB=IB-ICBO,Transferprocessofcarriers,Weknowfromtransferprocessofcarriers,generallyICICBO,2.Currentrelationships,sinceIE=IB+IC,IC=InC+ICBO,3.ThreeTypesofCircuitConfigurations,Comment-emitter,emitterisacommonterminal,brieflyCE;
Comment-base,baseisacommonterminal,brieflyCB;
Comment-collector,collectorisacommonterminal,brieflyCC;
3.1.2NPNTransistor:
Forward-ActiveModeOperation,Inordertousethetransistorasanamplifyingdevice,thetwoconditionsmustbesatisfied:
Internalcondition:
Impurityconcentrationinemitterregionismuchlargerthanthatinthebaseregion.Baseregionmustbeverynarrow.Externalcondition:
B-Ejunctionisforwardbiased.B-Cjunctionisreversebiased.,Forthepnptransistor,itisthecomplementarydevicetothenpntransistor,soallthevoltagespolaritiesandcurrentsdirectionsaretheoppositetothenpntransistor.,3.1.3Current-VoltageCharacteristics,1.InputcharacteristicofCE,iB=f(vBE)vCE=const,(TakingCEcircuitase.g.),
(2)WhenvCE1V,vCB=vCE-vBE0,B-Cisreversebiased,someelectronsbegintosweepintocollector,recombinationdecreasesinbase,soIBreducesundersamevBE,curveshiftstoright。
(1)whenvCE=0V,itissameasforwardexponentialrelationofadiode。
3.1.3Current-VoltageCharacteristics,2.TheoutputCharacteristicofCE,iC=f(vCE)iB=const,3.1.3Current-VoltageCharacteristics,2.OutputcharacteristicofCE(Transistorcharacteristic),iC=f(vCE)iB=const,Fourregionsforcharacteristic,3.1.3Current-VoltageCharacteristics,2.OutputcharacteristicofCE(Transistorcharacteristic),iC=f(vCE)iB=const,Fourregionsforcharacteristic,3.1.3Current-VoltageCharacteristics,2.OutputcharacteristicofCE(Transistorcharacteristic),iC=f(vCE)iB=const,Fourregionsforcharacteristic,3.1.3Current-VoltageCharacteristics,2.OutputcharacteristicofCE(Transistorcharacteristic),iC=f(vCE)iB=const,Fourregionsforcharacteristic,3.1.3Current-VoltageCharacteristics,2.TheoutputCharacteristicofCE,Current-voltagecharacteristicsforthecommon-emittercircuit,showingtheEarlyvoltage,3.1.3Current-VoltageCharacteristics,3.TheoutputCharacteristicofCB,WhytheVCBcanbenegative?
3.1.4BJTMainParameters,1.CurrentGain,
(1)Common-emitterdccurrentgainFF=(ICICEO)/IBIC/IBvCE=const,3.1.4BJTMainParameters,1.CurrentGain,
(2)Common-emitteraccurrentgain=IC/IBvCE=const,3.1.4BJTMainParameters,1.CurrentGain,(3)Common-basedccurrentgainFF=(ICICBO)/IEIC/IE,WhenICBOandICEOareverysmall,F,F.,(4)Common-baseaccurrentgain=IC/IEVCB=const,3.1.4BJTMainParameters,2.Reverse-biasLeakageCurrents,
(2)Collector-emitterleakagecurrentICEOICEO=(1+F)ICBO,
(1)Collector-baseleakagecurrentICBO,ICBOisthecollectorleakagecurrentincommon-baseconfiguration,whentheemitterisanopencircuit.,ICEO,3.1.4BJTMainParameters,3.BreakdownVoltage,BVCBOCollector-basejunctionbreakdownvoltageinopen-emitterconfiguration。
BVCEOBreakdownvoltagebetweencollectorandemitterinopen-baseconfiguration.,BVEBOBase-emitterjunctionbreakdownvoltageinopen-collectorconfiguration。
V(BR)CBOV(BR)CEOV(BR)EBOThesewillbealimitingfactorsinthesizeofthedcbiasvoltageswhichcanbeused.,ReviewQuestions,
(1)DuetoaBJThastwopnjunction,canweconjointwoback-to-backdiodestobeasaBJT?
Why?
?
(2)CanweexchangetheemitterandcollectorterminalsofaBJT,whenweuseitasaamplifyingdevice?
(3)WhywecallaBJTasacurrent-controlleddevice?
ReviewQuestions,4.Thevoltagevaluesforthreeterminalsaregiven,determinetheregionwhichBJToperatesin.
(1)VC=6V,VB=0.7V,VE=0V,
(2)VC=6V,VB=6V,VE=5.4V,(3)VC=6V,VB=4V,VE=3.6V,(4)VC=3.6V,VB=4V,VE=3.4V,?
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 英文 课件 ch3
![提示](https://static.bingdoc.com/images/bang_tan.gif)