How comparator works

　・In Japanese
Prerequisite knowledge
　・Operational amplifier

■What is a comparator?

A comparator is a circuit that compares the voltages of two input signals and outputs High (=supply voltage) if one voltage is higher than the other, and Low (0V) if it is lower. The circuit diagram is below.



If you look at it this way, you can see that the comparator has the same circuit as an operational amplifier. In fact, this is true, and it uses the characteristic of an operational amplifier that it outputs the power supply (or ground) according to the voltage difference between X2 and X1.

Therefore, if you want to use an operational amplifier as an amplifier circuit, use it as an inverting amplifier circuit.

List of related articles TOP MENU Electrical/electronic circuit ・Freewheeling Diode ・Alternating current ・Termination resistor ・CPU, LSI, IC, ASIC ・Adders, Subtractors ・H-bridge circuit ・Motor type ・Inverter ・AC-DC converter ・DC-DC converter ・Transformer ・ROM, RAM, register, cash ・open/short circuit failures ・Low-side, high-side driver ・Mechanism of electric shock ・Zener diode ・Rectifier circuit ・Pull up/down resistor ・Joule heat ・Solenoid valves, relays ・Comparator