(BQ) Part 2 book "Microelectronic circuits - Analysis and design" has contents: Feedback amplifiers, power amplifiers, active filters, oscillators, operational amplifiers, introduction to digital electronics, integrated analog circuits and applications. | CHAPTER 10 FEEDBACK AMPLIFIERS Learning Outcomes After completing this chapter, students should be able to do the following: • Describe the types and the properties of feedback amplifiers. • Describe the different feedback configurations, their properties, and circuit implementations. • Select the feedback configuration and analyze feedback amplifiers to meet specific requirements. • Design a feedback network to meet desired closed-loop gain, the input impedance, and the output impedance. • Determine the stability conditions of feedback amplifiers. • Apply the compensation techniques to stabilize an unstable amplifier. Symbols and Their Meanings Symbol A, Af Ao, Aof i i, i e, i f Ri, Rif Meaning Open-loop and closed-loop gain of an amplifier Low-frequency open-loop and closedloop gain of an amplifier Input, error, and feedback current signals Input resistances of an amplifier without feedback and with feedback Copyright 2011 Cengage Learning, Inc. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. 642 Microelectronic Circuits: Analysis and Design Symbol Ro, Rof Rie, Roe vi, ve, vf vo, vp, vg f, fD f, TL b, b F Meaning Output resistances of an amplifier with feedback and without feedback Equivalent input resistance and output resistance of an amplifier Input, error, and feedback voltage signals Oscillation, pole, and crossover frequencies of an amplifier Pole and dominant pole frequency of an amplifier Phase angle and transmission loop Feedback factor and current gain of a BJT Introduction Feedback is commonly used in amplifier circuits. A signal that is proportional to the output is compared with an input or a reference signal so that a desired output is obtained from the amplifier. The difference between the input and the feedback signals, called the error signal, is amplified by the amplifier. There are two types of feedback: • In negative feedback, the output signal (or a fraction of it) is continuously fed back
