|
slide 1010
& K! ~4 T# [7 N7 l1 d+ e2 N* s U' B* a6 D. Y! E
For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
0 r2 Z, d9 }- v+ f3 N$ s4 T6 a. j+ F- JThe signal bandwidth is determined by RF and not by the circuit gain.
, b- w- Z# m0 ~ pThe circuit gain is independently set with RS.( u' |8 n3 C; z/ P% D
The signal bandwidth remains stable for all gain settings .
$ T: T+ X F* o/ v- q+ JEven for unity-gain operation, an RF resistor is required.& k/ }" l6 O4 Z
The 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.5 u& q m/ n" o& S8 R
|
|