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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.
L* d* J. E, \( x" [- lThe signal bandwidth is determined by RF and not by the circuit gain.2 G1 m' O2 E+ n$ _1 k( W3 h
The circuit gain is independently set with RS.+ Q% K9 {9 [+ d- b9 N6 f
The signal bandwidth remains stable for all gain settings ./ a8 l# E9 E( F& }, Q3 k$ x
Even for unity-gain operation, an RF resistor is required.
8 A) w5 t, v: ?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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