Chapter 6. Feedback and Stability Theory
6.1. Why Study Feedback Theory?
The gain of all op amps decreases as frequency increases, and the decreasing gain results in decreasing accuracy, as the ideal op amp assumption (a ⇒ ∝) breaks down. In most real op amps, the open loop gain starts to decrease before 10 Hz, so an understanding of feedback is required to predict the closed loop performance of the op amp. The real world application of op amps is feedback controlled and depends on op amp open loop gain at a given frequency. A designer must know theory to be able to predict the circuit response regardless of frequency or open loop gain.
Analysis tools have something in common with medicine, because both can be distasteful but necessary. ...