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slide 1010
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2 P% D. x! ^/ U4 l; ~For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. / T8 g) a% b( I, I, V+ ^
The signal bandwidth is determined by RF and not by the circuit gain.
6 h3 N" r7 u# `3 B7 j; |- A1 U$ vThe circuit gain is independently set with RS.
2 Q7 ?' \& f. [( ^The signal bandwidth remains stable for all gain settings .7 F( d d& h: A$ R8 t7 W& i" V
Even for unity-gain operation, an RF resistor is required., y5 j& G4 _! Y# ]
The 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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