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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. % Q: P/ e0 |4 P2 ?& h7 f3 o7 l% F
The signal bandwidth is determined by RF and not by the circuit gain.
% r, E% S4 C) J6 P3 pThe circuit gain is independently set with RS.
x7 ?$ c1 m% x6 Y# z! rThe signal bandwidth remains stable for all gain settings .$ N% J- @, I5 V- t9 w# B$ G- m2 F! P
Even for unity-gain operation, an RF resistor is required.
: q4 Q4 @0 f! i2 @3 H7 J9 B {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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