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slide 1010
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1 ]4 J- ?, O0 Y2 hFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF. 8 D- o8 }' f0 N
The signal bandwidth is determined by RF and not by the circuit gain.
7 w+ j7 x. K- r, v! FThe circuit gain is independently set with RS.! t7 [) A3 d' m8 M- y) q
The signal bandwidth remains stable for all gain settings .
1 O$ x/ k# j% x' ]" f3 ?; @Even for unity-gain operation, an RF resistor is required.
) B- \3 T5 f: N. c) r; D' p4 qThe 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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