GATE DRIVING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce a loss in the case of on-driving a main switching element disposed at a high side.SOLUTION: A step-up driver 6 executes a charging operation for charging a capacitor C2 by an input voltage VIN2 and a step-up operation for outputting a step-up voltage by increasing one terminal voltage of the capacitor C2. In the OFF period of a transistor T1, a step-up control circuit 7 controls the operation of the step-up driver 6 to execute the charging operation. In the ON period of the transistor T1, the step-up control circuit 7 controls the operation of the step-up driver 6 to execute the step-up operation only in a predetermined time since the start point of time, and to execute the step-up operation only in the predetermined time at every predetermined refresh timing. A drive circuit 8 supplies the step-up voltage output by the step-up driver 6 to the gate of the transistor T1 to on-drive the transistor T1.