| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage conversion circuit and an overvoltage protection method that are able to automatically recover after it tries restraint of overvoltage if voltage at an output side or input side becomes temporarily excessive.SOLUTION: If output side voltage to which the voltage of a power supply 3 is stepped down becomes higher than a first voltage exceeding a control target voltage V0, a first FET 12 is forcibly turned to an off state, and after that if the stepped down voltage is dropped to a second voltage or below lower than the first voltage, the off state of the first FET 12 is removed. On the other hand, if the stepped down voltage becomes a third voltage or above higher than the first voltage, a second FET 14 is forcibly turned to an on state and a fuse 11 is melted down because there is a high probability that the first FET 12 is short circuited. |
