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slide 1010
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k7 n" `/ n! i5 a+ e6 RFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
+ I0 u4 T' p. I* C; S6 W* jThe signal bandwidth is determined by RF and not by the circuit gain.& l$ m) E' L9 J% S4 I* P! U
The circuit gain is independently set with RS.
3 P" {0 z( B8 E; T( m0 xThe signal bandwidth remains stable for all gain settings .
) m& d& ^8 a) G$ G9 t \/ B3 dEven for unity-gain operation, an RF resistor is required.
* h, Z( i6 d1 SThe 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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