Classes d'amplification

Objectives

 The aim is to learn how to design power amplifiers to achieve maximum efficiency.

Description

In order to interact with the world around us, it is often necessary to deliver significant power to a loading charge, which can be an electro-mechanical object to put it in motion (speakers, motors, piezo-electric elements, etc.), an antenna to transmit over long distances ... This task falls to the output stage of an amplifier. The latter must then be able to deliver a signal of high power without altering  its properties.

Also, the output stage must have the following properties:

-   a low output impedance to reduce gain loss.

- Provide high amplitude signals (voltage and current).

- Low distorsion.

-Transfer power to the load with maximum efficiency, implying that the

power dissipated by the output stage must be as low as possible. This is all the more important nowadays to make battery-operated devices more autonomous.

-Ability to dissipate power without degrading the performance of its active components

Targeted skills

-    Know how to recognize the different classes of amplifier.

-   Recognize the power yields of these classes A, B, AB, C, G, H, D.

-   Ability to analyse and design class A, B, AB, G, H and C power output stages in bipolar and CMOS technology.

-    Know how to choose the type of case for active components with/without heatsink using thermal theory to dissipate the required amount of  power.