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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. ' F9 }% C Q, U, E& }$ }
The signal bandwidth is determined by RF and not by the circuit gain." A+ r% E2 Q) L- ~+ f6 N- Q
The circuit gain is independently set with RS.$ l# T3 @, `$ _: N
The signal bandwidth remains stable for all gain settings .- Z. q& M9 }- q( K, V
Even for unity-gain operation, an RF resistor is required.. i2 C" c* Q/ l3 I
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.
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