Design and implementation of four-phase PWM dimming control for backlight inverter

This paper proposes a novel control scheme which possesses four-phase PWM dimming control loop for backlight inverter. We adopt four-phase PWM dimming control circuit to control the brightness of twelve lamps. Each phase can control four or two lamps. Circuit architecture is full bridge phase-shift circuit which can improve the total efficiency of the driving circuit. From the experimental results, we verify the performance that four-phase PWM dimming control will be better than the conventional single phase one. It can uniform lamp current, brightness and luminance.