Chapter 5Bipolar Junction Transistor (BJT)2025/11/27
1 2025/11/27 Bipolar Junction Transistor (BJT) Chapter 5
2Content5.0lntroduction5.1DeviceStructureandPhvsicalOperation5.2Current-VoltageCharacteristics5.3 The BJT as an Amplifier and as a Switch5.4BJTCircuits at DC5.5BiasinginBJTAmplifierCircuits5.6Small-SignalOperationandModels5.7Single-StageBJTAmplifiers5.8TheBJTInternalCapacitancesandHigh-FrequencyModel5.9FrequencyResponseoftheCommon-EmitterAmplifier5.10TheBasicBJTDigitalLogicInverter5.11TheSPICEBJTModelandSimulationExamplesSummary2025/11/27
Content 2025/11/27 2 5.0 Introduction 5.1 Device Structure and Physical Operation 5.2 Current-Voltage Characteristics 5.3 The BJT as an Amplifier and as a Switch 5.4 BJT Circuits at DC 5.5 Biasing in BJT Amplifier Circuits 5.6 Small-Signal Operation and Models 5.7 Single-Stage BJT Amplifiers 5.8 The BJT Internal Capacitances and High-Frequency Model 5.9 Frequency Response of the Common-Emitter Amplifier 5.10 The Basic BJT Digital Logic Inverter 5.11 The SPICE BJT Model and Simulation Examples Summary
IntroductionPhysicalStructureCircuitSymbolsforBJTsModesof OperationBasicCharacteristic2025/11/27
Introduction ⚫ Physical Structure ⚫ Circuit Symbols for BJTs ⚫ Modes of Operation ⚫ Basic Characteristic 2025/11/27 3
45.1TransistorTransistorisa three-terminal device,madeofsilicon(Germaniumwasearlyused)Therearetwotypes:NPNandPNPMetalMetalcontactcontactn-typep-typen-typeCollectorEmitterBaseEooCBaseCollectorEmitterEmitterCollectorregionregionregionregionregionregion(E)(C)Emitter-baseCollector-basejunctionjunctionOBBase(EBJ)(CBJ)(B)b)pnptransistor.a)npntransistorSimplifiedstructure2025/11/27
5.1 Transistor ⚫ Transistor is a three-terminal device, made of silicon (Germanium was early used) ⚫ There are two types: NPN and PNP 2025/11/27 4 a) npn transistor b) pnp transistor. Simplified structure
55.1Circuit symbol of the transistorOECBoBoocOEppnpn(b)(a)The emitter is distinguished by the arrowhead2025/11/27
5.1 Circuit symbol of the transistor 2025/11/27 5 The emitter is distinguished by the arrowhead