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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.
2 n3 m% ^4 \% YThe signal bandwidth is determined by RF and not by the circuit gain.
$ f. h9 L A! u" y7 FThe circuit gain is independently set with RS.) s8 n% E: T" g
The signal bandwidth remains stable for all gain settings .
& u4 }7 a& x, ~! |) OEven for unity-gain operation, an RF resistor is required.2 X4 a ]0 O- x1 T9 q
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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