POWER-FACTOR-IMPROVING PWM CONTROL DEVICE FOR SWITCHING POWER SUPPLY

摘要

Provided is a PWM control device that is for a switching power supply that has high output and a favorable power factor. A PWM control device that outputs a PWM signal to perform ON/OFF control of a switching element of a switching power supply that is configured to be capable of outputting current during both ON periods and OFF periods for the switching element. The PWM control device has: an input voltage detection part that detects an input voltage for the switching power supply; an input current detection part that detects an input current for the switching power supply; a difference outputting part that outputs a control voltage that corresponds to the difference between numerical values that are respectively proportional to the detected input voltage and input current; and a PWMIC that receives the control voltage as input and outputs a PWM signal that has ON periods that are proportional to the magnitude of the control voltage.