- 12 June 2006 -

Avago Technologies’ first colour controller with integrated RGB photosensor

Avago Technologies announced the industry’s first colour controller with an integrated color photosensor for backlighting LCDs for a variety of portable display devices. Avago’s new ADJD-J823 enables more accurate and consistent RGB LED backlighting, and richer colours than conventional technology. This solution is ideal for use in digital cameras, cell phones, PDAs, portable DVD players and display screens measuring 7 inches diagonal or smaller.

The device has a small footprint and low profile that allows it to fit easily into portable LCD devices where board space is limited. The 5x5x0.75mm integrated color management (ICM) device operates at voltages as low as 2.5V.

“Avago is the only company that provides a complete off-the-shelf colour management solution for LCD backlighting, combining RGB sensors, colour controllers and high-brightness LEDs,” said Lee Soo Ghee, vice president and general manager for Avago Technologies’ Optoelectronic Products Division. “By integrating the sensor and controller into one package, we are expanding the benefits of colour management to the growing array of applications using colour LCD screens in smaller consumer electronics.”
In LCD TVs, the use of LED backlighting with Avago’s award-winning illumination and colour management (ICM) control has been proven to offer 25 percent richer colours than conventional cold cathode fluorescent lamp (CCFL) backlighting. In addition, LED backlighting totally eliminates the traces of mercury found in CCFLs to meet European Union reduction of hazardous substances (RoHS) mandates.

The ADJD-J823 is a CMOS mixed-signal IC with integrated RGB photosensors designed to be the closed loop optical feedback device of an RGB LED-based backlighting system. This device also has a wide gain control and uses an algorithm to automatically select the optimum gain. A typical system consists of an array of red, green and blue (RGB) LEDs, LED drivers and the ADJD-J823. The device samples the light output from the RGB LED array, processes the color information and adjusts the light output from the RGB LEDs until the target color is achieved.

To do this, the device integrates an RGB photosensor array, an analog-to-digital converter front-end, a color data processing logic core and a high-resolution 12-bit pulse-width modulation (PWM) output generator. By employing a feedback system and the ADJD-J823, the light output produced by the LED array maintains its colour over time and temperature.

Avago’s ADJD-J823 colour controller with integrated colour sensor is priced at less than $10 in low volumes. Samples and production quantities are available now through Avago's direct sales channel and worldwide distribution partners.

www.avagotech.com/led