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slide 1010
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5 j8 S3 D6 J9 I( oFor a CFB amplifier the open-loop gain is ZT and its feedback factor is 1/RF, making the loop-gain TCFB = ZT/RF.
5 k+ K* v8 Y( s: i6 v4 s% Z, cThe signal bandwidth is determined by RF and not by the circuit gain.2 h4 u$ Q4 c' Q; }$ I8 v
The circuit gain is independently set with RS.
5 |# p+ U" I) z7 q- ?& M$ `, `. f' EThe signal bandwidth remains stable for all gain settings .
- `0 F% D- V, ]+ d& `Even for unity-gain operation, an RF resistor is required.
+ B. [, y) E- gThe 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.4 v% t4 u8 Q9 a# g/ f
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