|
slide 1010$ x. f/ a V1 ?- o' e F
8 I, e8 ^- F/ G+ K+ M* g; z
For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
M( {# Y0 Y. ]! iThe signal bandwidth is determined by RF and not by the circuit gain.
8 t- r/ C- q8 e/ ^7 ^: sThe circuit gain is independently set with RS.* y% o0 w& A/ Y- l% C: f
The signal bandwidth remains stable for all gain settings .
8 ^8 h: H/ M4 V2 ]Even for unity-gain operation, an RF resistor is required.
/ [7 w; u1 P, b6 A4 `+ j4 |2 `( XThe 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.& g6 j1 u9 n3 z% q [. d
|
|