PFC SIGNAL GENERATION CIRCUIT, PFC CONTROL SYSTEM USING SAME, AND PFC CONTROL METHOD

摘要

A PFC signal generation circuit for generating a PFC signal for controlling a PFC circuit having a first inductor (L1) connected to a first switch (NM1), and a second inductor (L2) connected to a second switch (NM2). The invention is equipped with: a counter (101) in which a count value is cleared on the basis of a first timing when zero current is detected in the first inductor (L1); a counter clear control circuit (202) for clearing the counter value after waiting until a cycle lower limit value, when the first timing is less than the cycle lower limit value; a first control signal output unit (109) for outputting a first PFC signal for turning the first switch (NM1) on at the timing when the count value is cleared; and a second control signal output unit (117) for outputting a second PFC signal for turning the second switch (NM2) on, on the basis of a second timing when zero current is detected in the second inductor (L2). As a result, it is possible to improve PFC circuit power factor correction.