A comparator has a first input, a second input, an output, a control electrode of a first hysteresis transistor coupled to the output, and a control electrode of a second hysteresis transistor coupled to the output. A method for testing the comparator includes: reconfiguring the comparator to be an amplifier with unity gain feedback; providing an input voltage to the input; providing a first voltage to the first hysteresis transistor to provide a first offset voltage; measuring a first output voltage at the output; removing the first voltage from the first hysteresis transistor; providing the first voltage to the second hysteresis transistor; and measuring a second output voltage at the output.