IR sensors save power

Silicon Laboratories introduces the QuickSense Si1102 proximity sensor and Si1120 proximity and ambient light sensor, both optimised for power efficiency in touchless human interface applications. Ideal for a wide variety of sensing applications, the Si1102/20 devices are well suited for products that can benefit from system power savings, tamper detection/proofing and gesture interpretation, such as portable electronics, IP phones, displays, kiosks, dispensers, interactive toys, clock radios, and other consumer and industrial products.

The QuickSense Si1102 sensor enables an electronic device to quickly gauge its proximity to the user. For example, it can detect if a handset is near a user’s face and adjusts the display and lighting accordingly. The QuickSense Si1120 infrared proximity and ambient light sensor can also detect the ambient light in the external environment, allowing screen backlighting to be dimmed, for example, saving power. When paired with the F700 and F800 touch sense microcontrollers (MCUs), the QuickSense solution enables smart motion sensing, giving designers a complete array of human interface technologies for their applications and fundamentally improving the end-user experience.

Historically, designing advanced human interface features into end products has been challenging and has introduced performance and power trade offs. Silicon Labs’ patented technologies and decade of infrared product design and manufacturing expertise has created a new method that eliminates the tradeoffs. Unlike competing approaches that require the infrared LED to be pulsed multiple times over a long period for accurate measurements, the Si1102/20 devices use a patented single-pulse proximity measurement technique to achieve up to a 4000x improvement in power efficiency, resulting in longer battery life, a critical feature in portable applications. With up to a 50 cm range (unaided by lenses), the Si1102/20 can easily power down displays and other functions when the user is not present. This power-saving capability is particularly appropriate for products such as appliances, security panels and IP phones.

The Si1120 device enables an innovative, patent-pending touchless proximity slider for gesturing, allowing end users to navigate without a physical touch but with simple gestures. The superior sensitivity that enables this touchless control feature has the added benefit of offering robust performance under a wide range of lighting conditions. It also enables the use of low-cost or low-profile infrared LEDs, often resulting in a significant system cost savings.

The Si1102 and Si1120 infrared sensor family is supported by the QuickSense Studio, a common development framework for all of the QuickSense devices including the F700 and F800 touch sense MCUs. The QuickSense Studio configuration wizard allows designers, using an intuitive software GUI, to select which functions they want implemented such as capacitive touch sense buttons, sliders and wheels, and then easily auto-generate the software to set up and calibrate these functions. Designers can also test their implementation and review a graphical display of the system performance.

‘Silicon Labs’ QuickSense human interface portfolio gives developers a robust, low-power human interface solution that’s easily configurable with a straightforward development environment,’ said Mark Thompson, vice president and general manager of Silicon Laboratories. ‘No other supplier is able to match the speed and accuracy of our sensors or to combine intelligent optical sensing with touch sense MCUs, making Silicon Labs a single source for advanced, easy-to-use human interface technology.’

Pricing and Availability
The QuickSense Si1102 proximity detector and Si1120 proximity and ambient light sensor are supported by reference designs and evaluation boards.

The Si1102 and Si1120 devices are available now in an 8-pin ODFN package and are priced at $0.90 and $1.05 (USD) respectively in 10k quantities.