System parameters comparison between four-phase and six-phase PWM dimming control for backlight inverter

This paper proposes two novel dimming control schemes which possess four-phase or six-phase PWM dimming control for backlight inverter. We adopt four-phase or six-phase PWM dimming control 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. Because six-phase PWM dimming inverters consume smaller input current than four-phase PWM dimming inverters at the same PDIM. So, it will cause that six-phase dimming presents smaller output lamp currents and a better smooth curve than four-phase PWM dimming. From the experimental results, we verify the performance that the six-phase will be better than the four-phase in dimming control.