Feedback Amplifiers: Stability Analysis

This lecture covers the stability analysis of feedback amplifiers, focusing on the frequency dependence of loop gain and the impact on amplifier stability. It discusses the stability criteria based on loop gain magnitude and phase, as well as gain and phase margins. The lecture also explores the effects of phase margin on closed-loop response and alternative approaches for stability investigation. Various amplifier types, such as voltage and current feedback amplifiers, are analyzed in terms of stability. The Butterworth and Chebyshev approximations for filter design are presented, emphasizing ripple in passbands and stopbands. The lecture concludes with detailed examples of Butterworth and Chebyshev transfer functions and their frequency responses.