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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.
" T8 g- l' G9 [& E" l, kThe signal bandwidth is determined by RF and not by the circuit gain.
# n; P4 r' [0 ]+ U" |( MThe circuit gain is independently set with RS.: l: z4 D. c) W0 y2 L# a5 u
The signal bandwidth remains stable for all gain settings .) z7 y4 }1 S+ r8 h8 {" Q8 c4 Q
Even for unity-gain operation, an RF resistor is required.
* }7 p1 A/ B9 \( @; OThe 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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