In electronics, a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger. A comparator typically includes two analog input terminals V+ and V− and one binary digital output V. It is commonly used in devices that measure and digitize analog signals, such as analog-to-digital converters. Comparators receive an analog signal and produce a digital bit. Comparators are evaluated based upon their ability to distinguish between tiny differences in input voltages as quickly as possible. In order to reduce the effect of input referred offset voltage, a preamplifier and latch circuit architecture is commonly used to achieve high speed and accuracy. Challenges to the optimal performance of comparators include the attenuation of accuracy due to offset voltage, the effect of kickback noise on resolution and excessive current consumption.
The figures are not to scale. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.