amplifier as comparatorAsk The Applications Engineer―31 By Reza Moghimi [reza.moghimi@analog.com] AMPLIFIERS AS COMPARATORS? Q. What is a comparator? How does it differ from an op amp? A. The basic function of a high-gain comparator is to determine whether an input voltage is higher or lower than a reference voltage―and to present that decision as one of two voltage levels, established by the output’s limiting values. Comparators have a variety of uses, including: polarity identification, 1-bit analog-to-digital conversion, switch driving, square/ triangular-wave generation, and pulse-edge generation. In principle, any high-gain amplifier can be used to perform this simple decision. But “the devil is in the details.” So there are some basic differences between devices designed as op amps and devices designed to ……