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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.
5 j! r6 V- p% h( u* ?The signal bandwidth is determined by RF and not by the circuit gain.
5 Z6 X7 ~( f$ J; V& n( E- JThe circuit gain is independently set with RS.7 N: P4 z H$ O1 x4 m& G
The signal bandwidth remains stable for all gain settings .7 ?: z) R' y7 o
Even for unity-gain operation, an RF resistor is required.
) c) l6 Y. i5 e9 m- }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.% j0 d3 z, ^ Y& ` S0 C
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