Final answer:
A comparator is an op amp circuit where the output voltage becomes either positive or negative, based on the voltages at its inverting and non-inverting inputs.
Step-by-step explanation:
The op amp circuit where the output is either a negative or positive voltage depending on a comparison between the input values is called a comparator. In this configuration, the op amp is set up without feedback to operate in an open-loop mode. When the voltage at the non-inverting input (positive input) is higher than the inverting input (negative input), the output will be at the positive saturation level, typically related to the power supply voltage. Conversely, if the voltage at the inverting input is higher than that at the non-inverting input, the output will be at the negative saturation level. Comparators are commonly used in electronic circuits for various logic decision operations and are integral in applications such as switching power supplies and analog-to-digital converters.