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slide 1010
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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 I. ~ S' Q, w7 `The signal bandwidth is determined by RF and not by the circuit gain.; Z# S4 T, F; M B6 z& { J' }
The circuit gain is independently set with RS.& `* P3 O4 F5 ^: O7 v
The signal bandwidth remains stable for all gain settings ." d2 o7 |. U5 \
Even for unity-gain operation, an RF resistor is required.
; A% @7 C* c' m" U$ PThe 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.
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