Patent ID: 9167647
Filing Date: 2015-10-20
Classification: H05B

Abstract:
1. A control circuit comprising: a power supply unit that includes a first switch which is turned on and off in response to a drive signal and a second switch which is turned on and off in response to a control signal, the power supply unit configured to generate a voltage to be supplied to a load by turning on and off the first switch and control a flow of a drive current to the load by turning on and off the second switch: a first controller configured to perform a first PWM control of the drive signal, based on a measurement value of the drive current; a second controller configured to perform a second PWM control of the control signal, based on an external signal; and a synchronous controller configured to synchronize an on-period of one period of the control signal to be a multiple of one period of the drive signal, wherein, during the on-period of the control signal, an inductor current for generating the drive current is cut off for a portion of every period of the drive signal.