Backlight driver of liquid crystal display device and method for driving the same to maintain stability of the duty ratio of the pwm signal driving the backlight

Abstract

A backlight driver and a method of driving the same are disclosed, which remove an unstable duty ratio by filtering an input PWM signal so as to prevent backlight flicker although the input PWM signal becomes unstable. The backlight driver includes a duty ratio detector for detecting a duty ratio of an input pulse width modulation (PWM) signal; a duty ratio filter for detecting a difference between a current duty ratio received from the duty ratio detector and a previous duty ratio, determining whether the detected duty ratio difference satisfies a preset reference condition, selecting one of the current duty ratio and the previous duty ratio, and outputting the selected duty ratio; and a PWM generator for generating an output PWM signal obtained when a selected duty ratio from the duty ratio filter is reflected in an input synchronization signal, and outputting the output PWM signal to a backlight unit.