Product focus: low-cost ams tri-stimulus color sensor characterizes biologically influential blue light

Sensor has range of applications supporting health and wellness in lighting and smart buildings.

In recent years scientists have discovered that the spectral content of illumination light has effects on humans; for example, a blue-heavy lighting spectrum in the evening can cause sleep problems and, conversely, being exposed to a blue-heavy spectrum (although preferably not in the evening) can boost cognitive performance. The ability to quickly characterize the spectrum of lighting fixures relative to these factors at a low cost can be useful in medicine, research, and industry.

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Now, ams (Premstaetten, Austria) has introduced a tri-stimulus sensor ( model number AS7264N) that provides measurements of color that closely match the human eye's response to the visible light spectrum. The company says the sensor also accurately measures blue-light wavelengths, which researchers have linked to important health effects such as disruption or management of the circadian rhythm, accelerated eye aging, and eye strain.

Provided in a 4.5 x 4.7 x 2.5 mm land grid array (LGA) apertured package, the small size of the sensor makes it well suited for testing luminaires and connected sensor packs; it is expected to be used in emerging applications of human-centric lighting and smart building control.

The sensor is based on the ams AS72xx product platform, which includes a family of light and color sensors from near-UV to near-IR for spectral and lighting applications. The family's tri-stimulus color sensors use on-wafer silicon interference filters to create individual spectral channels matching the characteristics of the XYZ standard observer model as specified by the CIE 1931 standard. The AS7264N supplements that with two additional blue light filters, providing the capability to accurately measure the intensity of blue light at both the 440 nm and 490 nm wavelengths.

The low-cost board-mounted AS7264N sensor allows the implementation of novel light control functions in luminaires, displays, and smart building automation or management systems. By incorporating this sensor into their product, lighting and building automation sensing manufacturers can use real-time smart color monitoring to measure and respond to end-users' exposure to blue light wavelengths.

The AS7264N sensor provides digital color measurement outputs over an I2C interface. The device's silicon interference filters, have minimal drift over time and temperature and enable lifetime end-device calibration. Programmable on-chip LED drivers enable direct control of synchronized electronic shutter functionality.

The AS7264N is available for sampling at $4.50 per unit in quantities of 1000 units. In addition, an evaluation board for the AS7264N color sensor is available from the ams ICdirect online store. For sample requests and more technical information, see

Source: ams

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