Dual-axis hi-g accelerometer for airbags

The AIS1120SX / AIS2120SX is a central acceleration sensor with a single or dual axis sensing element and an IC interface able to provide acceleration information to a master control unit via an SPI protocol.

The sensing element, capable of detecting the acceleration, is manufactured using a dedicated process developed by ST to produce inertial sensors and actuators in silicon.

The IC interface is manufactured using a BCD process that allows a high level of integration. The device is factory trimmed to better tune the characteristics of the sensing element with the acceleration information to be supplied.

The AIS1120SX / AIS2120SX has a full scale of ±120 g. The acquisition chain consists of a C/V converter, a full-differential charge amplifier, a 2nd order ΣΔ analog-to-digital converter and a digital core, which includes filtering, compensation and interpolation, control logic and SPI protocol generation.

The differential capacitance of the sensor is proportional to the proof mass displacement; thus, by sensing the differential capacitance, the position of the sensor is determined. Then, since the mass position is known, and the position is related to the input acceleration, the input acceleration can be easily deduced.

The device is available in a plastic SOIC8 package and is guaranteed to operate over a temperature range extending from -40 °C to +105 °C.

Key Features

  • AEC-Q100 qualified
  • 3.3 V single supply operation
  • 14-bit data output
  • ±120 g full scale
  • Slow and fast offset cancellation
  • Embedded self-test
  • Selectable low-pass filter
  • SPI interface
  • ECOPACK® compliant
  • Extended temperature range -40 °C to +105 °C


Technical Documentation

Product Specifications
Description Version Size
DS11250 DS11250: MEMS automotive acceleration sensor: single/dual-axis with SPI interface 3.0 1 MB
Technical Notes & Articles
Description Version Size
TN0018 TN0018: Surface mounting guidelines for MEMS sensors in an LGA package 6.0 214 KB
Design Notes & Tips
Description Version Size
DT0053 DT0053: 6-point tumble sensor calibration 1.0 464 KB

Publications and Collaterals

Description Version Size
MEMS automotive sensors - Making our cars safer and more comfortable 1.0 773 KB
Description Version Size
MEMS and Sensors, Smart solutions for IoT and enhanced user experience 1 MB
Support & Community

Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
AIS2120SXTR ActiveSO-8AutomotiveEcopack2

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.