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slide 1010
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+ C# D7 l3 K6 W6 g* @For a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. # D' V% U, M( F, p! Z% j! t0 U
The signal bandwidth is determined by RF and not by the circuit gain.( N* z+ b2 M9 O- w; s* U
The circuit gain is independently set with RS.8 z& s3 S; T9 I, J7 h" \
The signal bandwidth remains stable for all gain settings .5 w% J2 }" t$ r5 _% V
Even for unity-gain operation, an RF resistor is required.+ o, [4 f; V' l$ |6 J, T
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.; z( v- m9 [& ~
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