| 摘要 |
PROBLEM TO BE SOLVED: To achieve rapid discharge without increasing an area in a protective circuit that is turned off at system failure.SOLUTION: A protection circuit is connected between a power supply terminal and an output terminal, and turns off an output transistor for outputting a current to a load connected to the output terminal when a failure occurs in a system. The protection circuit has a first discharge unit which is connected between a gate electrode of the output transistor and the power supply terminal, and discharges electric charges of the gate electrode until a potential of the gate electrode becomes equal to a power supply potential, when a failure occurs in the system; and a second discharge unit which is connected between the gate electrode and a source electrode of the output transistor, and discharges the electric charges of the gate electrode until the potential of the gate electrode becomes equal to an output potential, when a failure occurs in the system. When detecting the failure in the system, the protection circuit discharges electric charges of the gate electrode of the output transistor until the potential of the gate electrode becomes equal to the power source potential, and discharges an electric charge of the potential of the gate electrode of the output transistor until the potential of the gate electrode becomes equal to the output potential. |
