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slide 1010$ i7 ], ?9 t$ [+ ~
+ V8 O3 ]' l/ 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.
7 M2 [1 m) U# I1 O1 @* @The signal bandwidth is determined by RF and not by the circuit gain.
- F" `* y, K1 f/ r8 G$ W; P; ^The circuit gain is independently set with RS.6 v3 t. K/ s/ f4 m4 z& @
The signal bandwidth remains stable for all gain settings .: `- x8 k8 }5 j) D! Z% I. @
Even for unity-gain operation, an RF resistor is required.
9 d. h4 ~4 K6 W7 |2 B( F% kThe 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.4 E* M1 ?2 A) M( i/ p
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