부산대학교 도서관

According to one embodiment, a circuit includes an amplifier, first and second capacitors, a switch and a monitoring-comparator. The amplifier amplifies source and drain voltages to output first and second amplified-signals. The first and second capacitors are connected to the amplifier's first and second terminals. The first and second amplified-signals are outputted from the first and second terminals. The switch forms first and second loops when a switching-transistor is OFF. The switch supplies a common-reference-voltage to the first and second loops to store charge in the first and second capacitors. The switch ends the first and second loops based on a gate-signal when the switching-transistor is ON. The monitoring-comparator compares first and second inputs. The monitoring-comparator outputs a signal depending on a comparison result when the switching-transistor is ON. The first and second inputs are input through the first and second capacitors.