ABSTRACT
A comparator is a functional circuit block that compares the relative levels of two signals. The comparator’s output signal provides a logic “1” or “0” depending on the result of the comparison.
The ideal comparator is perfectly accurate and instantly provides the correct output. Again, real life intrudes and gives us limits. Finite gain and non-zero propagation delays result in delays between the input signal being applied and the output signal being available. Input offsets result in errors in the comparison. However, these problems can be overcome, and many circuits can be built from the basic comparator. Oscillators, d/a converters and a/d converters all use some form of comparator, and operational amplifiers are comparators with frequency compensation.
