Analog Circuits

Lecture topics

First we refresh some basics from the module Electrical Engineering-3. Here we take a look at the temperature dependence of our semiconductor components. Then we discuss the function of the MOS transistor, whereby we look more closely at secondary effects such as the substrate effect in extension to the ET-3, and also at capacitances, small signal model and frequency response.

In section 4 of the lecture the 3 basic circuits, gate, source and drain circuit are explained. Each circuit concept has specific advantages, which are used in different amplifier concepts and for adaptation to the signal source or load. The chapter concludes with a study of the differential input stage and an overview of some CMOS operational amplifier topologies.

Chapter 5 of the lecture deals with the frequency response characteristics of amplifiers with feedback. Here we start with the Miller theorem and its effect and meaning in real circuits. The most important basic circuit from section 4, the source circuit, we now take a very detailed look at its AC characteristics. In order to describe the AC behaviour of circuits, the Laplace transformation is used, which we will briefly repeat here in addition to the system theory from the basic study.

In part 6, the 2-stage operational amplifier is constructed from a differential stage and a source circuit. The frequency response behavior the frequency response compensation is derived and conditions for the stability of the feedback amplifier are considered.

In sections 7 to 9, the operational amplifiers are used to build more complex circuits. These include various types of oscillators (LC oscillators, quartz oscillators in chapter 7), phase locked loops (PLL of type I and type II in chapter 8), as well as a brief insight into switched capacitor circuits (chapter 9).