A comparator includes a comparison circuit and a positive feedback circuit. The comparison circuit generates a comparison signal by comparing an input signal and a reference signal. The positive feedback circuit generates an output signal based on the comparison signal, such that the output signal transitions more rapidly than the comparison signal. The positive feedback circuit includes a first circuit configured to electrically connect a first power supply voltage to a conversion node in response to a transition of the comparison signal and electrically disconnect the first power supply voltage from the conversion node in response to a transition of the output signal, a second circuit configured to electrically connect a second power supply voltage to the conversion node in response to the transition of the output signal, and an output circuit configured to generate the output signal based on a voltage of the conversion node.