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slide 1010
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- q7 ~3 a5 a* ]( B. zFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
3 c$ W, S% D" u7 I! i: OThe signal bandwidth is determined by RF and not by the circuit gain.
9 D% K- Y. W7 wThe circuit gain is independently set with RS.
; C0 Y, Z2 w$ ]1 a5 ~# PThe signal bandwidth remains stable for all gain settings ., n; F! |4 R6 Y2 Z# b* B6 `
Even for unity-gain operation, an RF resistor is required.% [; L3 x9 b. \1 O5 i4 U
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.! J+ t+ S% T* \4 T
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