Feedback amplifier
From Wikipedia, the free encyclopedia.
A feedback amplifier is an amplifier which uses a feedback network, generally for improving performance (gain stability, linearity, frequency response etc.). Feedback can be negative or positive. Negative feedback (NFB), first invented by H. S. Black (pat. 2,102,671), is as a rule much more useful. The idea of this invention is simple: if NFB depth is big, overall response of the whole system can be very close to inverted feedback network response. As feedback network can be simple a passive, high degree of stability and linearity can be obtained. The most widely-known realisation of this principle in electronics are circuits, based on operational amplifiers (Op-Amps), such as the old uA741 or LF411.
