| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive circuit of a power semiconductor element which can adequately restrain a surge voltage generated by a parasitic inductance, with a comparatively simple circuit configuration. SOLUTION: When an input signal changing to a low level is supplied, an MOSFET (M1) 49 is turned off and an MOSFET (M2) 51 is turned on via a level shift circuit 47. A power semiconductor element 30 is to be driven to a low level. Gate charges of the element 30 starts discharge via a resistor 55. At the same time, an MOSFET (M4) 63 is turned on by an output of an MMV circuit 45. The gate charges of the element 30 starts discharge via a resistor 67, and the gate charges are discharged quickly. when drain voltage reaches a drain voltage which corresponding to the vicinity, where a drain current of the element 30 starts to decrease, the drain voltage is detected by an MOSFET (M3) 61, and the MOSFET (M4) 63 is made to turn off. The gate charges are discharged only through a resistor 55. The discharge becomes gentle, and di/dt is made small, so that a surge voltage is restrained within a small range.
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