Feedback and frequency response
John C.M. Lam · Focal Press eBooks · 2023
This chapter covers the analysis of the feedback and frequency response for audio and linear amplifiers. Depending on the polarity of the feedback signal, feedback can be negative or positive. Positive feedback drives the circuit into oscillation and it should be avoided. On the other hand, negative feedback results in reducing an amplifier’s gain. Negative feedback in four configurations is discussed in this chapter. The four configurations include (a) series-shunt, (b) shunt-shunt, (c) series-series and (d) shunt-series. The discussion is focused on how the negative feedback is a way to trade off gain for improvement to other properties of the amplifier, such as desensitizing the gain, modifying the input and output impedances, reducing nonlinearity, noise, distortion, and broadening the bandwidth.