Ams introduces new solutions for color stabilization and maintenance of lighting devices

     Ams introduces the AS7221 Intelligent Lighting Manager with all-white light and sunshine capture capabilities. A new addition to AMS 'smart Lighting Manager family, the Sensing Lighting ™ family, the AS7220 combines a precisely calibrated color sensor with an intelligent sensing lighting engine to maintain the output of warm and cold white LED strings in a closed loop. This allows the light source to automatically adjust the color and lumen changes caused by LED color drift and output lumen attenuation to maintain the color and output lumen of the light source. Output lumen decay and color drift are natural results of LED aging, ambient temperature changes, and drive changes.

     In the mainstream lighting system application markets, such as commercial, industrial and high-end residential areas, manufacturers often must use carefully selected leds to achieve the required CCT. By applying precision senser-based algorithms, AMS 'AS7220 Smart Lighting Manager creates high-quality, stable lighting using cold and warm white leds that are not carefully selected.

     The AS7220 can be easily integrated into LED lighting systems. On the production line, when the required CCT and maximum output lumen value are imported into the AS7220, it automatically controls the LED output in the fixture or light source to achieve closed-loop control of color and lumen. LED string power control can be achieved either through a multi-channel power supply by digital switching, or through a combination of a PMW controlled current with a standard 0-10 volt or PWM input dimming ballast or driver single-way power supply.

     "One of the ongoing challenges for the LED lighting industry is how to maintain consistent color and light output over the changing ambient temperatures and consumer expectations of LED service life," said Tom Griffiths, senior marketing manager at AMS Semiconductor. Leds perform very well in the first few years of use, and in long-term use there will be predictable deviations in color and brightness. In addition, leds develop very rapidly, and the leds used in the same model of lamps may not be the most cost-effective choice within a year of mass production, which leads to greater differences between lamps and lamps.

     "By adding closed-loop sensing control to their products, light source manufacturers can be freed from technological and material supply constraints, reducing material costs, improving consistency between products, giving them a greater choice of materials, and providing more accurate light quality over the life of their products," said Griffiths.

     Using an external AMS ambient light sensor, the AS7220 enables automatic daylight capture via a standard 0-10 volt dimming input interface. The Smart Lighting Manager also provides a standard space occupancy sensor interface for intelligent dimming control and energy saving planning.

     The AS7220 is equipped with the industry's first embedded CIE XYZ tri-stimulus color sensor, whose output data can be accurately mapped directly into the CIE 1931 color space, achieving accurate and robust control of the CCT of the light source. The nano-optical interference filter deposited on the AS7220 wafer is extremely stable and will hardly age due to changes in time and temperature.

     The AS7220 uses an LGA package with a size of only 4.7 mm x 4.5 mm x 2.5 mm, which includes an optical window with a viewing Angle of ±20.5°. By using the logic function integrated on the chip, the typical accuracy of the CCT measured by the chip after factory calibration is.002 du 'v "in the range of -40 to +85 degrees Celsius (roughly 2-3 order McAdam ellipses).