Catalyst delivers new high-resolution brightness, quad-mode LED drivers for enhanced LCD backlight control
(Product News, 30 Apr 2008 )
Catalyst Semiconductor continues to expand 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 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 constantly 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, to produce a richer user experience. 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 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 save significant board space and costs since they come in a low profile, 3mm x 3mm, 16-pad TQFN package and do not require additional capacitors, as do existing four-mode LED drivers.
The CAT3647 and CAT3648 join the following devices in Catalyst’s Quad-Mode family of LED drivers:
the CAT3604V four-channel LED driver with PWM dimming interface; the CAT3636 six-channel (1-wire EZDim interface with 32 dimming levels); the CAT3644 four-channel and CAT3643 three-channel devices (1-wire EZDim interface with six dimming levels); and the CAT3637 six-channel (1-wire EZDim interface with 16 dimming levels).
