MEMS acceleration sensors for wearables

A family of MEMS acceleration sensors from Bosch Sensortec is said to offer high performance and ease of integration in compact packages. The BMA456 and BMA423 are specifically designed for motion and fitness tracking in wearables.

The acceleration sensors include an optimised step counter for wearables integrated directly in the sensor, with no additional external microcontroller required.

Power consumption of the step counter is low, typically less than 30μA, which helps maximise battery life in portable devices. The sensors can be used to put wearables into sleep mode even during step-counting, thereby helping to reduce overall power consumption.

The sensors can also be used for advanced gesture recognition, such as tilting of the wrist, and can detect activities like running, walking and standing still.

The BMA456 provides higher performance, with 16bit resolution, 120μg/√Hz noise, and a total offset over its lifetime of 20mg. Temperature coefficient of offset is ±0.3mg/K, ensuring activity tracking remains accurate under all conditions.

The acceleration sensors are housed in compact packages measuring 2 x 2mm.