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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.
* q3 z# x& Q' u. A4 V, q+ ZThe signal bandwidth is determined by RF and not by the circuit gain.
* {' n% i" f/ PThe circuit gain is independently set with RS.
6 E6 {, W+ l( Y4 K- V# l. O7 {The signal bandwidth remains stable for all gain settings .
6 I& S$ O1 d& m' ]# sEven for unity-gain operation, an RF resistor is required.2 }& u' ?1 R h. r( k
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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