| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of a risk of increasing of a surge when processing for avoiding flowing of an excessive current to a voltage control type power switching element S is performed. <P>SOLUTION: A comparator 54 compares a voltage drop across a resistor 52 due to a current output from the sense terminal ST of a power switching element S with a threshold voltage Vref to acquire a large/small relation. Consequently, it is determined whether the current (collector current) flowing to the power switching element S exceeds a threshold. When it is determined that the threshold is exceeded, a switching element 56 is turned on to limit the gate voltage of the power switching element S almost to the breakdown voltage of a Zener diode 58. A resistor 42 for discharging is connected between the cathode of the Zener diode 58 and the gate of the power switching element S. <P>COPYRIGHT: (C)2010,JPO&INPIT |
