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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. & J% K# j) z( y4 `
The signal bandwidth is determined by RF and not by the circuit gain.8 P* i; i' }# v3 Z. {
The circuit gain is independently set with RS.6 r/ f, y8 B8 `: w, x% x4 j5 r4 I! Z
The signal bandwidth remains stable for all gain settings .
5 L! N$ U: n$ j& Q# S; X, _$ x9 MEven for unity-gain operation, an RF resistor is required.
3 w, `3 m8 p. gThe 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.3 z. }! D3 c) O) m3 G3 P) K7 _9 L
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