Comparator

Within Protection Logic systems, a comparator is a critical component that continuously monitors and compares measured values (such as voltage, current, temperature, or pressure) against predefined setpoints or reference values. Its primary role is to detect when a parameter exceeds safe operating limits, triggering protective actions like alarms, shutdowns, or corrective control signals to prevent equipment damage or hazardous conditions.

The comparator receives two analog input signals: one representing the actual measured parameter (e.g., from a sensor) and the other representing a fixed reference or setpoint voltage. An internal operational amplifier or dedicated comparator IC amplifies the voltage difference between these inputs. When the measured input exceeds the reference input by a small threshold (the input offset voltage), the output rapidly switches from a logic low state to a logic high state (or vice versa, depending on configuration). This digital output signal is then used by subsequent logic circuits to initiate protective responses.