Smart Lighting Sensor Boosts Color Stability

The AS7220 Smart Lighting Manager from ams enables a new generation of higher-quality LED-based lamps and luminaires by using closed-loop sensing to maintain more accurate correlated color temperature (CCT) and lumen output while also lowering system bill of materials costs.

 

Debuting as the latest member of the ams Cognitive Lighting Smart Lighting Manager family, the AS7220 combines a precise calibrated-for-life color sensor with an intelligent Cognitive Lighting Engine for standalone closed-loop maintenance of  the output from strings of warmer and cooler white LEDs. The result is a luminaire which automatically adjusts for the color shift and lumen depreciation of LEDs as a natural result of aging, operating temperature changes and driver variation over lifetime.

 

The AS7220 is easy to integrate into LED lighting system designs. After the desired CCT and/or full-output lumen values are programmed into it on the production line, it autonomously implements closed-loop color and output control of the LEDs inside a luminaire or lamp. Control of the power supplied to LED strings is implemented via either digital switching of multichannel power supplies, or through a combination of PWM current steering combined with an analog or digital output to standard single-channel 0-10V or PWM-input dimming ballasts or drivers.

 

The AS7220 is pre-configured for optional operation with an external ams ambient light sensor to additionally provide for autonomous daylight harvesting using standard 0-10V dimming inputs. The Smart Lighting Manager also provides a direct interface to standard occupancy sensors to enable intelligent dimming control and energy-saving schemes.

 

Accurate and stable CCT control is enabled by the AS7220’s industry-first embedded tri-stimulus CIE XYZ color sensor, which directly maps the sensor channel data to the CIE 1931 color space. Nano-optic interference filters deposited on the die of AS7220 devices offer high stability and virtually no degradation over time and temperature. The sensor system’s LGA package, which measures just 4.7mm x 4.5mm x 2.5mm, includes a built-in aperture with a ±20.5° field of view. Using logic capabilities integrated into the device, the chip is able to deliver factory-calibrated CCT values typically accurate to within .002 du’v’ (approximately 2-3 Macadam steps) across its -40 to +85 degree C operating temperature range.

 

The AS7220 Smart Lighting Manager is available now in production volumes. Unit pricing is $2.81 in order quantities of 10,000 units. An evaluation kit for the AS722x family is available from the ams ICdirect online store. For more technical information, go to http://www.ams.com/Smart-Lighting-Manager/AS7220

Suggested Articles

An accelerometer measures the rate of change of an object’s velocity to monitor its movement.

From cell phones to industrial manufacturing, knowing when an object (or a person!) is nearby is a basic sensing requirement.

Compact and rugged sensors from Balluff monitor temperature of fluids and compressed air.