A gate driver 28 performs a normal charging operation for a power MOSFET 14 by driving a charge pump 90 solely, when a low-level control signal S1 (ON signal) is received during a normal state. On the other hand, if a low-level control signal S1 (ON signal) is received during a load anomaly state, an urgent charge FET 92, as well as the charge pump 90, is turned on when a load current IL exceeds a second anomaly threshold current ILfc, so that a rapid charging operation is performed.