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slide 1010
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- S# Y( r; |: nFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. * \7 l0 y8 _) o5 J, X# u' @
The signal bandwidth is determined by RF and not by the circuit gain.5 i. l0 G+ l% {$ Z. ]; S0 R; a
The circuit gain is independently set with RS.2 n% B0 r& |% C+ H$ t" ~6 z0 Y
The signal bandwidth remains stable for all gain settings .
4 K) z$ i, D; e( u' S2 yEven for unity-gain operation, an RF resistor is required.1 I$ a+ v' R4 o: [# I, H. v8 S
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." |" |- N k3 l3 D: c5 _; h4 F
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