PFC CONTROLLER, SWITCHING REGULATOR AND POWER SUPPLY CIRCUIT

摘要

A PFC controller controls switching of switch elements of booster chopper circuits arranged in parallel. The PFC controller is provided with a circuit (SLOG) for generating another switch signal (GD_S) having a shifted phase to a switch signal of one switch element. The circuit is provided with a first counter (COUNTM) which counts clock signals by a cycle unit of one switch signal; a second counter (COUNTS) which counts the clock signals by a cycle unit having a prescribed phase difference to the one switch signal; and a first register (REG1) which holds the first counter count value that corresponds to a high-level period of the one switch signal. Other switch signals turn on other switch elements upon count start of the second counter, and turn off such switch elements in timing when a count value of the second counter accords with a value held by the first register. A circuit scale is small and operation accuracy is not easily greatly affected by process fluctuation.