A novel method for determining open-loop parameters in feedback amplifiers

A novel method for determining open-loop parameters, such as unity-gain frequency and phase margin, in feedback amplifiers is given. It is based on relations between open-loop and closed-loop configurations and is very useful for evaluating the above parameters in a unity-gain amplifier from a simple measure of its closed-loop 3-dB cut-off frequency and the respective phase for a given feedback factor, /spl beta/.