| 摘要 |
PROBLEM TO BE SOLVED: To perform appropriate protection from increase of a gate voltage in the case where a transistor falls into an overcurrent state or the like, in a configuration for driving a gate of the transistor with a constant current.SOLUTION: A constant current circuit 12 outputs a constant current toward a gate of an IGBT 6. An N-channel voltage output transistor 13 is interposed in a forward direction on a route from the constant current circuit 12 to the gate of the IGBT 6. A gate reference voltage generation circuit 11 is configured to generate a gate reference voltage and output it to a gate of the voltage output transistor 13, and switches a voltage value of the gate reference voltage between two stages. A control section 4 operates the constant current circuit 12 and drives the gate of the IGBT 6 with the constant current in the case of turn-on. At a time point of turn-on start, the control section 4 sets the gate reference voltage to a first setting value and in switching timing, the control section 4 then switches the gate reference voltage to a second setting value higher than the first setting value on the condition that it is not an overcurrent state. |
