Comparator

In electronics, a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger. It has two analog input terminals ${\displaystyle V_{+}}$ and ${\displaystyle V_{-}}$ and one binary digital output ${\displaystyle V_{\text{o}}}$. The output is ideally

${\displaystyle V_{\text{o}}={\begin{cases}1,&{\text{if }}V_{+}>V_{-},\\0,&{\text{if }}V_{+}<V_{-}.\end{cases}}}$

A comparator consists of a specialized high-gain differential amplifier. They are commonly used in devices that measure and digitize analog signals, such as analog-to-digital converters (ADCs), as well as relaxation oscillators.