| 摘要 |
A low-cost PFC converter capable of detecting an inductor current including a DC component and performing appropriate correction of a power factor with low loss includes a diode bridge that rectifies an AC voltage input from an AC input power supply Vac, a series circuit including an inductor and a switching element, a rectifying and smoothing circuit that is connected in parallel to the switching element and that includes a diode and a smoothing capacitor, and a digital signal processing circuit that performs on/off control on the switching element so that an input current input from the AC input power supply Vac has a similar waveform with respect to an AC voltage. A current flowing through the inductor during an off period of the switching element is detected using a current detecting resistor, and a decreased voltage of the current detecting resistor is sampled at the middle of the off period of the switching element, thereby detecting an average value of the input current.
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