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slide 1010
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, K- Y7 U2 ?0 @" {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 ~, Q, ?% j; ?5 ~ Q6 e; t8 ?The signal bandwidth is determined by RF and not by the circuit gain.
. e1 R6 P0 C8 p! n5 NThe circuit gain is independently set with RS.) ^4 J# G& y* H; D7 e5 O. B& N/ f
The signal bandwidth remains stable for all gain settings .+ |, w. ]1 U( Z( P
Even for unity-gain operation, an RF resistor is required.
' J8 c n5 l! i' O/ QThe 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.8 r X1 s4 k k
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