MEMS based pressure sensor measures height from the sea-level
STMicroelectronics has introduced a new pressure sensor that allows mobile phones and other portable devices to calculate their vertical elevation relative to sea-level with very high accuracy. This means that the mobile device will know not only on which floor of a building it is located, but almost on which step of the staircase.
ST says its new pressure sensor can accurately measure air pressure from 260 millibars, which is the typical air pressure at a height of around 10 km (about 1,500 m higher than the summit of Mount Everest) to 1,260 millibars, which is the typical air pressure at 1,800 m below sea-level, about half the depth of the deepest mine ever dug. 3x3mm sized sensor operating in low voltage and consuming low power can be used in smart phones, sports watches, and other portable equipment, as well as in weather stations and automotive and industrial applications. ST says the LPS331AP has already been adopted for use in Samsung’s latest and most advanced smartphone, probably Galaxy S3!
“Since launching the Consumerization Wave of MEMS devices, we have developed and delivered devices able to detect gravity, acceleration, angular rate, and the Earth’s magnetic field,” said Benedetto Vigna, Executive Vice President, Analog, MEMS & Sensors Group, STMicroelectronics. “All these sensors help smart consumer devices detect and react to motion. Now we are introducing a device that senses the weight of the atmosphere and will help consumer products recognize if a person or an object is moving up and down.”
Main technical features of the LPS331AP:
High resolution, low-noise sensor able to detect differences within centimeters of altitude variation;
ST’s proprietary VENSENS technology providing high burst resistance, up to 20 times full scale;
Selectable ODR from 1 Hz to 25 Hz;
Low power consumption: low res. mode 5.5µA, high res. mode: 30 µA;
Supply voltage: 1.71 to 3.6 V;
A temperature range extending from -40 °C to +85 °C;
Integrated temperature sensor enabling temperature span compensation;
Fab calibration of pressures and temperatures, eliminating the need for in-house calibration of shipped devices;
Supplied in a 3x3x1mm plastic land-grid-array (HCLGA-16L) package. The package is holed to allow external pressure to reach the sensing element.
The LPS331AP is now in volume production at a typical price of $2.6 in quantities of 1,000 units. Samples and evaluation kits are available to support design-in and shorten time-to-market. ST’s pressure sensor evaluation kit consists of a motherboard (STEVAL-MKI109V2) and a plug-in module, the STEVALMKI120V1 adapter including the LPS331AP pressure sensor.