Bipolar Junction Transistor

BASIC ELECTRONICS
MODULE 3

Bipolar Junction Transistor
Prepared by

H V Balachandra Achar
Senior Lecturer,
Dept. of E&C Engg.,
M I T, Manipal

Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Syllabus
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Introduction to Bipolar Junction Transistor
BJT Operation
BJT Configurations
Tutorials
BJT Biasing
Tutorials
BJT Amplifier
Tutorials

Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Reference Books
1. “Electronic Devices and Circuit Theory” by
Boylestad & Nashelsky,
2. “Integrated Electronics” by Millman & Halkias,

Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Introduction
• Solid state transistor was invented by a team of scientists at
Bell laboratories during 1947-48
• It brought an end to vacuum tube era
• Advantages of solid state transistor over vacuum devices:
– Smaller size, light weight
– No heating elements required
– Lower power consumption and operating voltages
– Low price

Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Introduction

Figure showing relative sizes of transistor, IC and LED

Figure showing different transistor packages
Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Introduction
• Bipolar Junction Transistor (BJT) is a sandwich consisting of three layers of two different types of semiconductor
• Two kinds of BJT sandwiches are: NPN and PNP

Department of Electronics and Communication Engineering,
Manipal Institute of Technology, Manipal, INDIA

Introduction
• The three layers of BJT are called Emitter, Base and Collector
• Base is very thin compared to the other two layers
• Base is lightly doped. Emitter is heavily doped. Collector is moderately doped
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