Comparator unit for a flash analog-to-digital converter

摘要

A high speed comparator unit for a flash A/D converter in which a bank of comparator units compare simultaneously an analog input voltage with equally spaced reference voltages, and an encoder ROM produces digital signals based on the comparator unit's outputs. The comparator unit includes a two-stage cascode configuration and a level shifter configuration which effectively reduces the miller-effect of the comparator unit.