6-axis high-performance accelerometer/gyroscope runs at “always on” power levels

September 10, 2014 // By Graham Prophet
From ST, this 6-axis inertial combination MEMS sensor (3A+3G) typically consumes 0.8 mA at 100 Hz, claimed to be at least 20% better than competition and 3-times lower than current ST generation.

The power-efficient, low-noise device is suited to Internet of Things, wearable, indoor navigation, and handheld applications, ST says, with state-of-the-art performance figures including 0.6 mg RMS noise at ODR = 104 Hz, and typical gyro noise density of 7 mdps/√Hz at 10 Hz. The device has the largest-available data buffering, with time stamp, at 8 kBytes.

This is the first iNEMO Ultra product - an always-on, high-performance 6-axis combination accelerometer and gyroscope that sets new standards for device and system power efficiency, signal noise, and performance in motion sensors. Together with ultra-low-power STM32 microcontrollers, the LSM6DS3 combos will create new possibilities for the development of battery-powered smart sensor systems to be embedded in mobile and wearable devices and innovative objects for the Internet of Things (IoT).

Measuring 2.5 x 3.0 x 0.8 mm, iNEMO Ultra 6-axis inertial-sensor combo (3-axis accelerometer/3-axis gyroscope) delivers industry-leading noise performance as noted above, while managing system power to a level 20% more energy-efficient than the best alternative combos in low-power mode.

This is in part, due to the large “smart” FIFO memory of 8 kBytes) — at least 2 times larger than other products. This flexible memory allows the LSM6DS3 to save and batch more data before waking up the system processor, saving overall system power.

The LSM6DS3 will be delivered as an optimised 2-chip system-in-package featuring high-performance 3-axis digital accelerometer and 3-axis digital gyroscope with integrated power-efficient modes down to 0.6 mA in always-on working mode.

Detailed performance figures include;

Accelerometer = 90 μg/√Hz (typ) in high-performance mode with Output Data Rate (ODR) @ 104Hz and 0.6 mg-rms (typ) in high-performance mode ODR @104 Hz.

Gyroscope = 0.007 °/s/√Hz (typ) in high-performance mode @10 Hz and 0.07 °/s-rms in high-performance mode with ODR @208 Hz.

The LSM6DS3's event-detection interrupts enable efficient and reliable motion tracking and context awareness that is implemented in hardware. This allows for recognition of free-fall events, 6D orientation, tap and