SYNCHRONOUS RECTIFICATION DEVICE AND ALTERNATOR EMPLOYING THE SAME

摘要

PROBLEM TO BE SOLVED: To perform screening or the like of a capacitor defect after assembly by configuring a rectification device of a synchronous rectification MOSFET to prevent a current from flowing to a control circuit by cutting off power supply from the outside under a predetermined condition.SOLUTION: A rectification device 107 includes: a rectification MOSFET 101 which performs synchronous rectification; a control circuit 106 which inputs a voltage between a pair of a positive electrode side main terminal TK and a negative electrode side main terminal TA of the rectification MOSFET 101 and discriminates ON/OFF of the rectification MOSFET 101 on the basis of the input voltage; and a capacitor 104 which supplies power to the control circuit 106. The control circuit 106 includes a cut-off circuit 105 which inputs the voltage between the pair of main terminals of the rectification MOSFET 101, cuts off the power supply to the control circuit 106 when the input voltage between the pair of main terminals is above a first voltage, and cancels the cut-off of power supply to the control circuit 106 when the input voltage between the pair of main terminals is below the first voltage.SELECTED DRAWING: Figure 1