Mitigation of sampling distortion in regenerative comparators by passive source degeneration

Presented is a scheme for regenerative comparators to suppress the induced input-dependent sampling distortion and also to alleviate the impact of substrate noise coupled to the comparator. The proposed scheme is based on the concept of source degeneration and is realised by incorporating a resistor at the source terminal of the sampling transistors. The scheme is evaluated with transient simulations, by characterising the output waveform jitter of the comparator with eye diagrams, and it is proven effective in the presence of high input signals and substrate noise.