Always-on 6-axis inertial motion sensors

December 03, 2013 // By Graham Prophet
Lowest-power devices make portable products more sensitive and long-lasting; this 6-axis MEMS device runs sensor fusion and application software on-chip within a power budget said to be previously unattainable

STMicroelectronics' latest family of always-on 6-axis inertial motion sensors offers lowest power requirements, ultra-compact packaging and design flexibility. It features a 6-axis inertial motion-sensing device that can run all sensor-related functions as well as customer-specific application software onboard while consuming up to 40% less power than existing solutions.

These 6-axis sensors deliver motion sensing that can detect orientation and gestures to empower application developers and consumers with features and capabilities more sophisticated than simply orienting their devices for portrait and landscape mode. Taking 360-degree panoramic photos simply by slowly rotating your mobile phone or scrolling through maps with a sweep of your arm are just two of many new tasks enabled by this family of sensors.

Combining motion sensing with an ARM Cortex microprocessor core, the LSM6DB0 6-axis smart sensor is the latest device in ST’s iNEMOTM smart-sensor family. It is the only device on the market that can efficiently run all of the sensor-related features specified in Android KitKat 4.4 on board – saving power, enabling faster reaction time and simplifying device design. Thanks to the open microprocessor architecture, device manufacturers can integrate their own custom sensor application software.

The sensors use true 6-axis sensing, where both the 3-axis accelerometer and 3-axis gyroscope are manufactured on the same chip. They operate synchronously at the same output data rate, fusing correlated, true six-degree-of-freedom motion and not just separate acceleration and angular-rate inputs. This implements state-of-the-art motion tracking; efficient and reliable contextual awareness; a low-power, accurate pedometer; precise orientation; and heading on any portable device. The design also drives accelerometer zero-g offset down by an order of magnitude to a maximum of 100 mg and gyroscope rate noise down to 0.008 dps /√Hz typical at low full-scale. The power-efficient sensors consume less than 2 mA and come in ultra-compact 3 x 3 x 0.8 mm (LSM6DS0, LSM6DS1) or 3 x 3 x 1 mm (LSM6DB0) packages.

The LSM6DS1 and LSM6DB0 both