STMicroelectronics has introduced a family of high-g acceleration sensors for advanced airbag systems. These micro-machined devices detect the rapid deceleration of the vehicle during a crash and send instant information to the airbag control unit. The AIS1xxxDS peripheral-sensor accelerometers provide single-axis in-plane motion sensing across five ranges, from ±20 g up to ±400 g. An on-chip IC interface converts the deceleration data into a high-resolution digital bit stream transmitted with high reliability to a dedicated microcontroller chip through a standard DSI protocol. Algorithms evaluate the situation and decide whether or not to deploy the airbag within a few milliseconds. The sensors operate within an extended temperature range from -40 to 125°C. They comply with the stringent AEC-Q100, a stress-test qualification for automotive integrated circuits established by the AEC (Automotive Electronics Council). The sensor in the airbag accelerometer is fabricated on the 8inch MEMS line. The electrical part benefits from the high level of integration and specific control of parasitic currents made possible by the Silicon-On-Insulator technology. Samples are currently available and production will begin in 2012.
