Analysis and Comparison of Distortion of Miller and Feed-Forward Opamps in Negative Feedback

The distortion performance of two-stage Miller and feed-forward operational amplifiers (opamps) under negative feedback are studied, and their inter-modulation strengths near the band-edge compared analytically. Recognizing that distortion increases with frequency, intuitive analytical models to estimate distortion near the band-edge of the closed loop system are developed. It is established that feed-forward configuration is fundamentally more linear than its Miller counterpart at the band-edge of the closed loop system, where the loop gain of both the topologies are identical.