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slide 1010
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, {1 o# H4 E4 a' ^" l8 BFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
5 O5 d2 x D, B# ^( `4 JThe signal bandwidth is determined by RF and not by the circuit gain.
8 A; \! |2 {. g- S+ r* tThe circuit gain is independently set with RS.
9 y( h& x. U0 [( g- iThe signal bandwidth remains stable for all gain settings .9 ~. Q# T( l9 H# \& X
Even for unity-gain operation, an RF resistor is required.* T% M% @0 h# 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.
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