## Simple Way Of Teaching Transistor Amplifiers

Conference

2000 Annual Conference

Location

St. Louis, Missouri

Publication Date

June 18, 2000

Start Date

June 18, 2000

End Date

June 21, 2000

ISSN

2153-5965

Page Count

9

Page Numbers

5.547.1 - 5.547.9

Permanent URL

https://peer.asee.org/8698

70

#### Abstract NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Session 2793

Simple way of teaching transistor amplifiers Bogdan M. Wilamowski University of Wyoming

Abstract

For small signal analysis a simple change from commonly used tranconductance gm to transresistance rm=1/gm leads to a significant simplification of all equations. Moreover these equations are much easier to memorize since they have a form of resistor ratio for CE (CS) and CB (CG) configurations and the form or resistor divider for CC (CD) configuration. With presented approach most of students are able to read diagrams and to understand the effect of each element change on the circuit performance. Students are not lost with messy equations, but they are in control of their design and they know which parameters they have to change in order to change behavioral characteristics.

I. Introduction

Students usually have significant difficulties in memorizing all the equations for calculation of gain, input and output resistances for transistor amplifiers [1][2][3][4]. They do relatively well if a common source (emitter) is used, but they are lost when other configurations are considered. In the paper, a simple way for analysis of transistor amplifiers is introduced. At first, approximate and accurate methods for circuit biasing are discussed including both BJT and FET amplifiers. All transistor circuit analysis should be always performed in the following order: 1. Biasing point calculation 2. Calculation of small signal parameters 3. Gain, input and output resistance calculation This paper is also organized in that way. iD D

G + + VGS - S VGX RS - X

Fig. 1 Biasing calculation for FET transistor with series of resistor RS

II. Biasing calculation

Calculation of the biasing point for bipolar transistor circuits are relatively straightforward and usually students do not have a problem with that. If it would be possible one should

Wilamowski, B. M. (2000, June), Simple Way Of Teaching Transistor Amplifiers Paper presented at 2000 Annual Conference, St. Louis, Missouri. https://peer.asee.org/8698

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