|
slide 10105 F! B) I* F' f+ t( [
7 K n- h2 {( d5 I; J+ ]
For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. Z# j9 L3 J" `% t8 S
The signal bandwidth is determined by RF and not by the circuit gain." ~) E3 ^ o. ^8 ?5 R* |$ ]2 ^
The circuit gain is independently set with RS.5 M- q) i1 i6 @& i* T1 ~5 J2 Z: l, U
The signal bandwidth remains stable for all gain settings .
5 o. c7 }6 i2 a( T s6 VEven for unity-gain operation, an RF resistor is required.
. |* @, C- D$ g, E; y7 G8 CThe 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.
, z. H) J- }9 I# ?$ b) r |
|