| 摘要 |
PROBLEM TO BE SOLVED: To largely reduce the power consumption of a step-up PFC control unit.SOLUTION: A step-up PFC control unit 1 includes: an AC switch bridge circuit 101 that performs full-wave rectification on an AC voltage Va; and a step-up circuit that increases the full-rectified voltage Vr. The AC switch bridge circuit 101 includes plural AC switches 11-14; and an AC switch control circuit 54 that controls ON/OFF state of the AC switches 11-14. When a gate-source voltage is higher than a threshold value, the AC switches 11-14 allow a current to flow from the drain to the source or the source to the drain according to the polarity between the drain source and the voltage; when a gate-source voltage is lower than a threshold value voltage, the AC switches 11-14 shut off the current from flowing from the drain to the source; and when the gate voltage with respect to the drain voltage is larger than the threshold value voltage, the AC switches 11-14 allow the current to flow from the source to the drain. |
