Accelerometers measure linear acceleration. They can also be used for specific purposes such as inclination and vibration measurement. MEMS accelerometers embed several useful features for motion and acceleration detection, including free-fall, wakeup, activity/inactivity detection, and 6D/4D orientation.
STMicroelectronics' AIS2IH is an AEC-Q100-qualified, low-power, three-axis linear accelerometer that leverages manufacturing processes already used to produce micromachined accelerometers. It targets non-safety automotive applications including anti-theft, telematics, infotainment, tilt/inclination measurement, and vehicle navigation. It can also address emerging automotive applications such as digital drive recorders, driver monitoring, vertical level sensing in vehicle suspension, and door automation.
The AIS2IH has user-selectable full scales of ±2 g/±4 g/±8 g/±16 g and is capable of measuring accelerations with output data rates from 1.6 to 1600 Hz. It features an integrated 32-level first-in, first-out (FIFO) buffer, allowing the user to store data to limit intervention by the host processor.
With five different operating modes, including one high-performance mode (HPM) and four low-power modes (LPMs), the device offers application flexibility. It can switch from low-power modes to high-resolution, high-performance modes on-the-fly to optimize resolution and power consumption for the exact application requirements at any time.
AIS2IH has a dedicated internal engine to process motion and acceleration detection, including free-fall, wakeup, and activity/inactivity. The part’s embedded self-test capability allows the user to check the functioning of the sensor in the final application.
ST's low-g accelerometers have power-saving features and an extended temperature range that suits them for non-critical automotive applications. Power-saving features include low-power mode, auto wakeup function, and FIFO buffer that can be used to store data, thus reducing the host processor’s loading and system power consumption. Operating current at 3 V is 110 μA in HPM and 0.67 μA in LPM at 1.6 Hz. The embedded 32-level FIFO and the motion- and activity-detection functions contribute to keeping the system-level power consumption within a tight budget.
The AIS21H can measure accelerations with output data rates (ODRs) configurable in the range from 1.6 Hz to 1.6 kHz with embedded configurable digital low-pass and high-pass filters. Typical noise density is 90 µg/√Hz when operating in high-performance mode.
Other features include:
- A high-speed I²C/SPI digital output interface
- Two independent programmable interrupts
- Low noise down to 90 µg/√(Hz) in high-performance mode
- Extended temperature range of −40 to 115 °C
- Supply voltage from 1.62 to 3.6 V
- Independent I/O supply
- Embedded temperature sensor
- Self-test
- 10000-g high shock survivability
The STEVAL-MKI218V1 is an adapter board designed to facilitate the evaluation of MEMS devices in the AIS2IH product family. The board offers an effective solution for fast system prototyping and device evaluation directly within the user’s own application. The STEVAL-MKI218V1 can be plugged into a standard DIL 24 socket. The adapter provides the complete AIS2IH pinout and comes ready to use with the required decoupling capacitors on the VDD power supply line.
The AIS2IH delivers low power consumption in a compact LGA-12 land-grid-array package with wettable flanks. The accelerometer is sampling now.