Santa Clara, Calif. Catalyst Semiconductor, Inc. has expanded its line of Quad-Mode fractional charge pump LED drivers with two high-resolution brightness devices that feature 32 dimming levels to provide enhanced LCD backlight control in emerging portable product applications. The new CAT3647 and CAT3648 address the need for high-resolution LCD control and longer battery life in cell phones, digital cameras and other handheld devices, where designers need to balance higher performance features with longer battery life.
The CAT3647 and CAT3648 give designers finer control of LED current and brightness with the ability to program in step increments as small as three percent. This is achieved via Catalyst's 1-wire EZDim programming interface, which supports 32 linear steps from full-scale brightness down to zero current.
The LED drivers are four-mode fractional charge pumps (1x, 1.33x, 1.5x, 2x), providing 10 percent higher efficiency and no added cost, compared to three-mode charge pumps, according to Catalyst. The CAT3647 drives three LEDs at 30 mA each and the CAT3648 drives four LEDs at 25 mA each, both with power efficiency as high as 92 percent. Both devices are available in low profile, 3 x 3-mm, 16-pad TQFN packages and do not require additional capacitors.
Pricing: The CAT3647 LED driver is priced at $0.64 each, and the CAT3648 is priced at $0.68 each, in quantities of 10,000.
Availability: Samples and evaluation kits are available now. Projected lead time for production quantities is currently six to eight weeks ARO.
Product information: CAT3647, CAT3648, and Quad-Mode LED drivers
Datasheets: CAT3647 and
Catalyst Semiconductor, www.catsemi.com