How to Prevent Flicker Caused by Burst Dimming

Abstract: The DS3881 and DS3882 CCFL controllers are used in automotive, industrial, and avionic applications to backlight LCD panels that require a high dimming ratio. These CCFL controllers use both analog lamp-current amplitude modulation and digital pulse-width burst-dimming techniques to achieve the high dimming ratio. The digital PWM burst dimming can, however, create visible flicker at very low dimming levels. This application note describes how to eliminate the flicker.