The LPS331AP is an ultra-compact, absolute piezoresistive pressure sensor from STMicroelectronics. It includes a monolithic sensing element and an IC interface able to take the information from the sensing element and provide a digital signal to the external world. The sensing element consists of a suspended membrane inside a single monosilicon substrate.
The device is capable of detecting pressure and is manufactured using a specific proprietary process called VENSENS. The VENSENS process allows a monosilicon membrane to be produced above an air cavity with controlled gap and defined pressure. The membrane is very small compared to traditional silicon micromachined membranes. Intrinsic mechanical stoppers prevent membrane breakage.
The IC interface uses a standard CMOS process. This allows a high level of integration to design a dedicated circuit, which is trimmed to better match the sensing element characteristics. The LPS331AP is available in a small, plastic land-grid array (HCLGA) package, and is guaranteed to operate over an extended temperature range from -40°C to +85°C. The package is holed to allow external pressure to reach the sensing element.
ST's pressure sensors are supported by an evaluation kit that consists of a motherboard (STEVAL-MKI109V2) and a plug-in module. The module includes the LPS331AP sensor (STEVALMKI120V1). Once the adapter is plugged in, the board can be connected to a host PC via USB, so the device’s capabilities can be easily evaluated via an intuitive graphic user interface.