Lecture
The influence of OOS on the parameters of the amplifier and its characteristics
Gain
Negative feedback reduces the gain of the amplifier by (1 + βK) times.
If βK >> 1, then the gain taking into account the feedback does not depend on the parameters of the amplifier itself, such feedback is called “deep”
input impedance will increase by - (1 + βK) times
output resistance will decrease by - (1 + βK) times
bandwidth will increase -
Negative feedback increases the stability of the gain, and improves the properties of the amplifier; decreases the level of nonlinear distortion.
Positive feedback properties (PIC)
• U = Uin + Uoc; Kos = K / (1- βK);
• gain, with the introduction of positive feedback increases;
• input impedance decreases;
• output resistance increases;
• bandwidth is narrowed;
• stability of the amplifier deteriorates;
• non-linear distortion increases.
Amplitude-frequency response with feedback
Amplitude response with feedback
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Electronics, Microelectronics, Element Base
Terms: Electronics, Microelectronics, Element Base