文档介绍：Chapter 3 Bipolar Junction Transistor (BJT) 1 SJTU Zhou Lingling Outline Introduction Operation in the Active Mode Analysis of Transistor Circuits at DC The transistor as an Amplifier Graphical Analysis Biasing the BJT for Discrete-Circuit Design Configuration for Basic Single Stage BJT Amplifier High frequency Model 2 SJTU Zhou Lingling Introduction Physical Structure Circuit Symbols for BJTs Modes of Operation Basic Characteristic 3 SJTU Zhou Lingling Physical Structure A simplified structure of the npn transistor. 4 SJTU Zhou Lingling Physical Structure A dual of the npn is called pnp type. This is the simplified structure of the pnp transistor. 5 SJTU Zhou Lingling Circuit Symbols for BJTs The emitter is distinguished by the arrowhead. 6 SJTU Zhou Lingling Modes of Operation Modes EBJ CBJ Application Cutoff Reverse Reverse Switching application in digital circuits Saturation Forward Forward Active Forward Reverse Amplifier Reverse active Reverse Forward Performance degradation 7 SJTU Zhou Lingling Basic Characteristics Far more useful than two terminal devices (such as diodes) The voltage between two terminals can control the current flowing in the third terminal. We can say that the collector current can be controlled by the voltage across EB junction. Much popular application is to be an amplifier 8 SJTU Zhou Lingling Operation in the Active Mode Current flow Current equation Graphical representation of transistor’s characteristics 9 SJTU Zhou Lingling Current Flow Current flow in an npn transistor biased to operate in the active mode. 10 SJTU Zhou Lingling