The LPS331APTR is an ultra compact absolute piezo-resistive Pressure Sensor for indoor and outdoor navigation. It includes a monolithic sensing element and an IC interface able to take the information from the sensing element and to provide a digital signal to the external world. The sensing element consists of a suspended membrane realized inside a single mono-silicon substrate. It is capable to detecting pressure and is manufactured using a dedicated process developed by ST called VENSENS. The VENSENS process allows to build a mono-silicon membrane above an air cavity with controlled gap and defined pressure. The membrane is very small compared to the traditionally built silicon micro-machined membranes. Membrane breakage is prevented by an intrinsic mechanical stopper. The IC interface is manufactured using a standard CMOS process that allows a high level of integration to design a dedicated circuit which is trimmed to better match the sensing element characteristics.
