Catalyst's Quad-Mode LED Drivers for Enhanced LCD Backlight Control in Portable Devices

(Product News, 23 Apr 2008)

Catalyst Semiconductor Inc. has expanded its line of patented, Quad-Mode fractional charge pump LED drivers with two new high-resolution brightness devices, featuring 32-dimming levels to provide enhanced LCD backlight control in emerging portable product applications. The 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 constantly need to balance higher performance features with longer battery life.

Featuring Catalyst's 1-wire EZDim programming interface, which supports 32 linear steps from full-scale brightness down to zero current, 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, to produce a richer user experience.

The new 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. The CAT3647 drives three LEDs at 30mA each and the CAT3648 drives four LEDs at 25mA each, both with power efficiency as high as 92 percent. Both devices come in a low profile, 3x3mm, 16-pad TQFN package and do not require additional capacitors.

Click here for more information on the CAT3647 LED driver

Click here for more information on the CAT3648 LED driver

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