| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protection circuit that can prevent the increase of a transistor capacity for driving a load. <P>SOLUTION: In this protection circuit 10, when a surge voltage is caused by turning off the power of a load 11, a Zener diode 31 is turned on and subsequently a charge-pump circuit 15 is turned on. Then, an output voltage of a prescribed value from the charge-pump circuit 15 turns on a MOSFET 13. As a result, a voltage impressed to the MOSFET 13 on the occurrence of the surge voltage can be suppressed, and the capacity increase of the MOSFET 13 can be controlled. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
