SENSORS - Ambient light sensing and proximity detection devices operate behind darkened glass - Embedded.com

SENSORS – Ambient light sensing and proximity detection devices operate behind darkened glass

Plano, Tex. – Texas Advanced Optoelectronic Solutions, Inc. has launched the first members of its next generation digital ambient light sensor (ALS) and proximity detection family designed to enable consumer electronics manufacturers to produce sleeker, more appealing and innovative product designs. The new devices eliminate the need for clear glass or plastic in front of the sensor or to drill holes/slots in the display, bezel or frame in order for light to reach the sensor.

Specifically designed to operate behind darkened glass or other translucent materials, the TSL2771 device family provides both ambient light sensing and proximity detection in a single device that consumes far less power than currently available comparable solutions. Proximity detection is ideally suited for touch-screen smart phones to automatically turn off the display or control other user functions. It can also be used in laptops, desktop computers and monitors to conserve energy and maintain information privacy when the user is not present. Other emerging applications for proximity sensing technology include touchless display controls activation and management as well as human gesture detection.

“The need for ambient light sensors to operate behind darkened glass or other translucent materials has emerged as a critical requirement in today's consumer electronic products,” said Carlo Strippoli, TAOS, Inc. Vice President of Sales & Marketing. “Consumers have become increasingly sophisticated and manufacturers need a way to be able to deliver sleeker, more compelling designs while still delivering the benefits of improved picture quality and reduced energy consumption that digital ambient light sensors provide.”

The TSL2771 Ambient Light Sensor and Proximity Detection device family incorporates an IR LED current-limited driver, analog-to-digital conversion (ADC), interrupt capability, multiple I2C interface voltage options, and flexible programming, allowing it to be configured into many different applications. As darkened glass or translucent materials can be transparent to IR wavelengths while attenuating visible light by 100 times or more, the device utilizes TAOS' patented dual-photodiode architecture that allows the sensor system to compensate for the increased IR component. When combined with the ability to adjust the analog gain settings up to 128X, the device excels in challenging low-light level applications.

“In many portable applications, battery life is critical,” said Kerry Glover, TAOS, Inc. Applications Manager. “Traditional proximity detection methods require a significant amount of power. With the new TAOS architecture, as few as one IR pulse is required for presence detection. This can provide 10x in power savings over traditional analog or other digital solutions.”

In applications requiring longer distance detection, an external driver can be utilized to boost the power such that a person can be detected in front of a monitor. A unique state machine allows the device to go into a lower power wait state, thereby having the high-power external detection running only a small portion of the time.

For applications requiring only ambient light sensing, this family of TAOS devices also includes the TSL2580/81 high-sensitivity ambient light sensors.

To accelerate time-to-market and reduce design-in effort, TAOS provides support for software device drivers and/or C-reference code as well as Evaluation Modules (EVMs).

The TSL27711 (3V bus) and TSL27713 (1.8V bus) are packaged in Dual Flat No-Lead (FN) packages.

The TSL2771 ALS and Proximity Detection and TSL2580/81 high-sensitivity ALS devices are available now from TAOS, Inc. and its authorized distributors.'Pricing for both the TSL27711 and TSL27713 is $1.07 in quantities of 1,000 pieces. The TSL2580 with SMBus interface and the TSL2581 with I2C interface are available in FN packages and are priced at $0.75 each in quantities of 1,000 pieces.

For more information on the TSL2771 device family visit http://www.taosinc.com/Productfamily.aspx?id=10&SD=ALSPD. TSL2580/81 data sheets are available at'http://www.taosinc.com/Productfamily.aspx?id=8&SD=als .

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