Date: 15/11/2010

Intersil and Nextreme develops reference design for energy harvesting apps

Intersil Corporation and Nextreme Thermal Solutions have developed a reference design for a self-powered, wireless strain gauge module using precision amplifiers and switches from Intersil.

Intersil explains that it is powered by thin-film thermoelectric technology, the gauge measures strain in locations that are not easily accessible, such as inside walls, in pipes, or under bridges, then transmits the measurements to a remote, easily accessible receiver.

The module consists of a strain gauge, an Intersil ISL28133 chopper amplifier, an Intersil ISL54051 low on-resistance switch, and an Si1012 wireless module. A 100µA (100 microamp) continuous current draw is sustained by the Nextreme TherMobility thermal energy-harvesting unit, and excess energy is stored in a capacitor until required. Once the module is installed, it will operate untouched throughout its lifetime.

The new reference design will be demonstrated at the Nextreme booth at the Energy Harvesting & Storage USA conference in Boston on November 15 and 16. The reference design and more information about the components used are available from Intersil Corporation's website at http://www.intersil.com/energyharvesting/ and Nextreme's site at www.nextreme.com/intersil.

The Intersil-Nextreme collaboration represents the first step in a joint program of wireless sensor network development for energy harvesting and ultra-low power systems.

Intersil says its ISL28133 chopper-stabilized op amp requires only 18µA during operation and low power and low voltage offset over temperature (75nV/ºC) and time are key features for energy harvesting applications. In addition, the small size (1.6mm x 1.6mm µTDFN package) of the ISL28133 and 1.8V supply voltage makes it an suitable choice to be paired with small, low powered sensors, which may need to be powered by energy harvesting devices, as per Intersil.