Chapter 13 : Bipolar Junction Transistors 13-0 Introduction 13-1 Current and voltage relationships 13-2 Common –emitter characteristics 13-3 Load –line analysis 13-4 pnp bipolar junction transistors 13-5 Large signal DC circuit models 13-6 Large signal DC analysis 13-7 Small –signal equivalent circuits 13-8 Common –emitter amplifiers 13-9 Emitter followers

13-0 Introduction

Fig. 5-1 General structure of npn BJT

Fig. 5-3 Current flow in a npn BJT

13-1 Current and voltage relationships

Equations of operation

Exercise 13-1

Another example

13-3 Load-line analysis of a common emitter amplifier

Load- line analysis of the amplifier (cont’d)

Example 13-2 : Load-line analysis of a BJT amplifier

Example 13-2 (cont’d)

Fig Circuit symbols for BJT

Fig Voltage polarities and current flow of BJT in the active mode

Fig. 5-2 A general structure of pnp BJT

Fig Current flow in a pnp BJT

Fig. 5-5 Large area equivalent circuit models for npn BJT in the active mode

Fig Early effect

Fig Hybrid Pi model for small signal operation

Fig T model for small signal operation

Fig Hybrid Pi small signal model with r 0

Pi and T model with r 0

The Widlar Current Mirror (p.653)

Another example