Modeling Opamp as comparator

This circuit is shared with intention for those who want to model comparator Response in a system. Opamp when used in positive feedback configuration, when inverting input voltage not yet reach triggering level, it act as non inverting amplifier circuit at right hand side. Once inverting input voltage exceed the triggering level, due to positive feedback, opamp operate as comparator until power down. I do saw this phenomenon once in my design works. One of the solution I found to make it back to an ideal comparator is using mosfet in common Gate configurations. I hope this model (circuit at left) helps others who need genuine comparator response for their idea. 3/12/2023 -> Added Comparison circuit to show transition of opamp from non inverting amplifier to comparator. Added pulse power supply to trigger the amplifier to comparator transition so that others understand the phenomenon.

published 2 years ago