What is a Comparator?

A Comparator is a circuit which accepts two voltages or currents and then switches the output showing which is bigger. Comparators are found in components like analogue to digital converters. Comparators are like operational amplifiers except a comparator is designed to operate with positive feedback and output saturated at one power rail or the other.

How a Comparator works.
A comparator samples two input pins and turns on the output when identifying a difference or similarity.
An example is when you have a minus voltage on the inverting Pin and a plus non-inverting. When the voltage, on the non-inverting equals the inverting voltage the Pin turns on. Normally the output Pin is open and switches to ground when the comparator is activated.

Why use a Comparator?
The primary use of a comparator is converting analog to digital (ADC). Two supply voltage are applied and the difference determines a high or low digital signal.

Types of Comparator.
Current sense, Differential / Dual differential, Dual / Dual CMOS, Dual voltage / General voltage, General purpose, Ground sense, High speed / high-speed CMOS, Low current CMOS, Low power / low voltage / low-power CMOS, Micro power, Nano power, Precision, Push/pull output, Quad differential, Rail to rail, Voltage, Window.

Mounting Types.
Surface mount
Through hole
Comparator power supply types.
Dual
Single

Various package types, pins, sizes, channels per chip, PSRR (power supply rejection ratio), CMRR (common mode rejection ratio) are all available.