On October 12, STMicroelectronics (ST) announced two new central airbag crash sensors that are configured as a single airbag electronics kit and can support the most demanding automotive applications and functional safety standards.

The released AIS1120SX and AIS2120SX are 120g horizontal single and dual-axis MEMS acceleration sensors that are mounted on the vehicle's ACU (airbag control unit) to analyze sensor data and operate safety devices.

Each sensor is equipped with two independent detection channels to enable redundant checking, ensuring optimal stability. It also features low-speed and high-speed offset removal functions and precise temperature compensation functions.

Ensuring the reliability of data evaluation is ensured by the ‘power-on self-test’ function and runtime diagnostic functions, which help to obtain the appropriate level of functional safety standards. Both sensors have a standard signal bandwidth of 400 Hz, which can be extended by the user to 1,600 Hz.

The precision mechanical elements for sensing are integrated into the same package as a 3.3V compatible interface IC capable of 14-bit digital SPI output. The AIS1120SX and AIS2120SX sensors have an extended temperature range of -40°C to +105°C.

ST's Airbag Electronics Solutions

Airbag system manufacturers can meet their system functionality requirements by using the new AIS1120SX or AIS2120SX central crash detection sensor in conjunction with a peripheral acceleration sensor, such as ST’s AIS1200PS, mounted in a bumper or door pillar. These sensors interact with the accompanying airbag system IC and security microcontroller to coordinate airbag activation.

There are three airbag system ICs to choose from: the L9678, L9679, and L9680. These devices integrate system power management functions, sensor interfaces, switch interfaces, and arming safety logic, and are responsible for decoding sensor data and sending the results to the microcontroller.

ST's SPC5 automotive microcontroller family, based on the 32-bit Power Architecture™, also includes Safety Line devices with up to 1Mbyte of Flash memory and a choice of single- or dual-core configurations. It optimizes system and diagnostic control functions with multiple DSPI channels, and in addition, it provides a fault collection and control unit (FCCU) and built-in self-test functions to satisfy the safety aspect of ASIL (Automotive Safety Integrity Level) level development.