|
slide 1010! e: ]; n3 m" K# V7 s) {
4 p; t9 R9 z( R& Q; M7 `. eFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
% q U* T$ _3 }' J o7 oThe signal bandwidth is determined by RF and not by the circuit gain.
: H: h) V) \1 N, cThe circuit gain is independently set with RS.# w- I) E7 a3 d7 `; L" r- d0 R
The signal bandwidth remains stable for all gain settings .2 F6 Q1 J4 L+ `& \4 g3 s/ M
Even for unity-gain operation, an RF resistor is required.; @# s, j" f2 v
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.
2 _7 I( S: a5 h |
|