| 摘要 |
PROBLEM TO BE SOLVED: To provide an overcurrent protection circuit capable of accurately detecting overcurrent condition to sufficiently guarantee elimination of heating, with no increase in the number of external components. SOLUTION: The overcurrent protection circuit is operated with inclusion of a first operation mode in which a capacitor is charged until a terminal voltage reaches a first voltage upon triggering of a power supply circuit, a second operation mode in which the capacitor is charged so that the terminal voltage rises from the first voltage to a second voltage according to the time length during which a current flowing an output transistor of the power supply circuit is above a predetermined value, and when the terminal voltage reaches the second potential, the power supply circuit is shut down, and a third operation mode in which, when the power supply circuit is shut down, the capacitor is charged until the terminal voltage reaches a third voltage, and when the terminal voltage reaches the third voltage, the power supply circuit is released from the shut-down state. COPYRIGHT: (C)2011,JPO&INPIT |
