Nonlinear analog components in MOS technology essentially include comparators and multipliers. They can ﬁnd applications in communication and instrumentation systems.
A comparator provides an output signal to indicate whether the input signal is higher or lower than a reference voltage, or equivalently, determines the sign of a voltage diﬀerence. Its output then assumes either the high or low level, depending on the relative magnitude of the input signals. In most applications, comparators are required to exhibit a high speed, a high gain, a high common-mode rejection, and a low oﬀset voltage.