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8 M! W, m( G2 r" ]For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. " r3 `5 U' C z
The signal bandwidth is determined by RF and not by the circuit gain.3 P$ `' Y8 }) m: F. G, h
The circuit gain is independently set with RS.
8 }9 O1 s; `9 @) m- t. s/ N" oThe signal bandwidth remains stable for all gain settings .
; M4 A) B; s- R: ~1 jEven for unity-gain operation, an RF resistor is required.
, W# I1 e6 P/ f9 m, v- qThe best practice when designing with CFB op-amps is to use the RF values given in the datasheet and to adjust the desired gain level through RS.
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