| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the number of components of a power-supply device having a PFC circuit. <P>SOLUTION: A PFC circuit 200 receives an AC voltage V<SB POS="POST">AC</SB>' from a rectifier circuit 10 and converts the AC voltage V<SB POS="POST">AC</SB>' into a DC voltage V<SB POS="POST">DD</SB>. A first switch SW1 is provided between an output terminal 12 of the rectifier circuit 10 and a second switch SW2. A control circuit 210 receives a feedback signal V<SB POS="POST">FB</SB>according to the DC voltage V<SB POS="POST">DD</SB>occurring on an output line OUT, a voltage detection signal V1 according to the AC voltage V<SB POS="POST">AC</SB>' from the rectifier circuit 10, and a current detection signal V2 according to a current I<SB POS="POST">M2</SB>flowing through the second switch SW2. The control circuit 210 switches the second switch SW2 and switches the first switch SW1 complementarily with the second switch SW2 so that the DC voltage V<SB POS="POST">DD</SB>approaches a predetermined target value and the waveform of the current detection signal V2 approaches the waveform of the voltage detection signal V1. <P>COPYRIGHT: (C)2013,JPO&INPIT |
