MEMS accelerometer operates under severe temperature and vibration

TDK Corp. has introduced the miniature Tronics AXO315 one-axis, closed-loop MEMS accelerometer with a 24-bit digital SPI interface in a SMD package. The company claims the force-rebalance MEMS accelerometer attains the performance of quartz sensors and outperforms commercial MEMS sensors.

The device targets applications requiring high accuracy and stability in demanding environments, such as servo inclinometers and dynamic inclinometers in industrial motion control units, IMUs and INS for GNSS-aided positioning, and navigation of manned and unmanned ground vehicles and trains.

Developed to provide high precision and high reliability in challenging environments, the AXO315 is a ±14 g range, in-plane linear accelerometer. The device delivers a one-year composite bias repeatability of 1 mg at temperatures ranging from -55°C to 105°C, and composite scale factor repeatability of 600 ppm under severe temperature and vibration conditions found in industrial, land, railway, naval and construction applications, according to the company.

In addition, the AXO315’s performance is equivalent to the incumbent analog quartz accelerometers and mechanical inclinometers, but at a fraction of their size (<0.8 cm³ vs. <10 cm³),  weight (<1.4 g vs. 50 g), and price (2-3× times cheaper), while remaining free from dual-use export control according to Annex 1 of Council Regulation (EC) No 428/2009, said TDK. This enables the device to offer a reduction in size, weight and cost of materials for industrial motion control units, inertial measurement units (IMU) and inertial navigation systems (INS).

Other features include bias instability of 4 µg, a velocity random walk of 0.006 m/s/√h, very low noise of 15 μg/√Hz, enabling high resolution and low error, and 4 g vibrations with an outstanding vibration rejection, said TDK.

The AXO315 offers an 80% gain in temperature stability compared to Tronics’ previous accelerometer generation, the AXO215. It also complements the existing lineup of Tronics’ high performance GYPRO digital gyros for high-performance IMUs and INS.

The AXO315 is housed in a lightweight 1.4 g hermetic SMD J-lead ceramic package (12 x 12 x 5 mm). Pre-production and customer sampling have started, followed by full production and availability through TDK’s distribution network in summer 2021. An Arduino-based evaluation kit is available to provide developers with improved testing functionalities such as output reading and recording, recalibration and digital self-tests.