An LED driver has been developed by austriamicrosystems AG and by LG Philips LCD. The AS3693 allows dimming of multiple segments of an LCD TV backlight for high contrast ratios and optimum picture quality. This block dimming causes only the required segments of the backlight to be on, rendering bright spots in the picture especially bright and dark parts completely black. The driver controls 16 LED channels independently via built-in pulse width modulation generators, while withstanding up to 50 V. Current is controlled with 0.5% precision. External clock and synchronizing inputs enable easy synchronization of the LCD backlight with the TV picture. Safety features include thermal shutdown, and open and short LED detection.