TDK Releases Force-Rebalance Digital MEMS Accelerometer

TDK Corporation announces that Tronics AXO 315, a miniature high-performance 1-axis closed-loop digital MEMS accelerometer, is now available for purchase at Digi-Key, Mouser and Farnell and its affiliates Newark and Element 14. The AXO315 sensor and its Arduino-based evaluation kit are now available globally from the three distributors’ websites.

AXO315 is a ±14 g range, in-plane linear accelerometer designed and developed to provide high precision and reliability in the most challenging environments, withstanding severe temperature and vibration conditions common in industrial, land, railway, naval, oil & gas and construction applications. It achieves a one-year composite repeatability of 1 mg, and a 600 ppm composite scale factor repeatability over temperatures ranging from -55 °C to +105 °C and under 4 g vibrations, with an outstanding vibration rejection. Performance is augmented by its superior Allan variance characteristics, with a basis instability of 4 µg, a velocity random walk of 0.006 m/s/√h and a very low noise of 15 µg/√ Hz, thus enabling high resolution and low error.

Its characteristics enable significant reduction in size, weight and cost of materials for a number of applications. These include: servo inclinometers and dynamic inclinometers in industrial motion control units, Inertial Measurement Units (IMU) and Inertial Navigation Systems (INS) for GNSS-aided positioning, and navigation of manned and unmanned ground vehicles and trains.

AXO315 features a force-rebalance architecture, a 24-bit digital SPI interface and an SMD package. Its performance is equivalent to the incumbent analog quartz accelerometers and mechanical inclinometers, but at a fraction of their size, weight, and price. It also outperforms all commercially available MEMS sensors components, and eases integration compared to analog sensors.

This product complements the existing lineup of the high-performance Tronics GYPRO® digital gyros for high-performance IMUs and INS. It comes in a lightweight 1.4 g hermetic SMD J-lead ceramic package (12 x 12 x 5 mm), enabling low-cost assembly and reliability on PCB, even in fast-changing temperature conditions.

The AXO315 accelerometers are manufactured, tested and calibrated at Tronics Microsystems’ facility in Grenoble, France. Evaluation of the sensors can be made through an Arduino-based evaluation kit that is specifically designed to provide developers with improved testing functionalities such as output reading and recording, recalibration and digital self-tests.

Glossary

• 1-year composite bias repeatability: typical bias error repeatability over 1-year in operation under temperature and vibrations.
• 1-year composite scale factor repeatability: typical precision over operating temperature during
  1-year in operation.
• Closed-loop / force rebalance: When the sensor is subjected to linear acceleration, the acceleration acts on the proof-mass, which is itself counterbalanced by applying voltages that generate electrostatic forces to rebalance the proof mass (closed-loop operation). The applied voltage is directly proportional to the input acceleration.

Main applications

• Servo-inclinometer for precise industrial motion and tilt control
• IMU and INS for ground and underground vehicles, trains and robots
• Test instrumentation

Main features and benefits

• High precision and fidelity with 1-year composite bias repeatability of 1 mg and a 600 ppm composite scale factor repeatability over temperature and vibrations (-55 °C to +105 °C, >4 g rms vibration), making it compatible with demanding applications such as train and vehicle localization,  heavy-industry and construction machines positioning and motion control, as well as test instrumentation.
• Force-rebalance closed-loop MEMS accelerometer with quartz sensors -equivalent performances 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).
• SMD component with digital SPI interface reducing the cost of integration and BOM: standard SMT assembly on FR4 board, no ADC required and easier system calibration.
• Non classified under dual use applications enabling civil and security usage without export license.

Further information on the products can be found here.