| 摘要 |
<p>In the present invention it becomes possible to cope with fluctuations in a power supply voltage when a capacitor necessary for coping with fluctuations in the power supply voltage has been omitted and also to cope with cases in which the power supply voltage is constantly low, thereby ensuring driving of an active element. In this invention, a gate driving device which drives a gate of an IGBT (3) includes: a first switch portion (20) which turns on the IGBT (3); a second switch portion (40) which turns off the IGBT (3); a current control portion (50) which controls the outflow of charge on the gate of the IGBT (3) to a ground line (12) such that a current flowing in the IGBT (3) is constant; a first protection circuit (30) which suppresses outflow of charge on the gate of the IGBT (3) to the power supply line (12); and a second protection circuit (60) which detects a prescribed fluctuation in an internal power supply voltage Vdc, and when the fluctuation is detected, interrupts the connection between the current control portion (50) and the ground line (12).</p> |
