Quad-Mode LED Drivers Enhance Backlight Control

Providing 32 programmable dimming level in 3% step increments, the CAT3647 and CAT3648 quad-mode LED drivers employ the company’s one-wire EZDim programming interface, which supports 32 linear steps from full-scale brightness down to zero current. Four-mode fractional charge pumps, 1x, 1.33x, 1.5x, and 2x, the devices deliver 10% higher efficiencies when compared to three-mode charge pumps. The CAT3647 drives three LEDs at 30 mA each and the CAT3648 drives four LEDs at 25 mA each, both with a power efficiency as high as 92%. The devices come in 16-pad TQFN packages measuring 3 mm x 3 mm and require no additional capacitors. Prices for the CAT3647 and CAT3648 are $0.64 and $0.68 each/10,000 piece, respectively. CATALYST SEMICONDUCTOR INC., Sunnyvale, CA. (800) 258-5991.