The Overview
In STMicroelectronics’ LSM6DSV16BX, designers of wireless hearables find a highly integrated sensor that purports to save space and power in end-products such as sports and general-purpose earbuds. It combines a six-axis inertial measurement unit (IMU) for head tracking and activity detection with an audio accelerometer for detecting voice through bone conduction in a frequency range that exceeds 1 kHz.
Who Needs It & Why?
In the true-wireless-stereo (TWS) hearables space, the race is on amongst OEMs to design smaller, more accurate end-products with lower power consumption. The LSM6DSV16B sensor brings that and a host of other high-end features to not only the TWS space, but also to other wearables such as smart glasses, hearing aids, and VR/AR headsets.
Under the Hood
That slew of high-end features makes the LSM6DSV16BX a candidate for TWS/hearable design upgrades. For one thing, the device contains ST’s Qvar charge-variation detection technology for user-interface controls such as touching and swiping. For another, the sensor embeds ST’s Sensor Fusion Low Power (SFLP) technology, specifically designed for head tracking and 3D sound,
It also includes the in-the-edge processing resources featured in ST’s third-generation MEMS sensors. These include the finite state machine (FSM) for gesture recognition, the machine-learning core (MLC) for activity recognition and voice detection, and adaptive self-configuration (ASC), which automatically optimizes performance and efficiency. These help to reduce system latency while saving overall power and offloading the host processor.
Together, the enhanced integration and in-the-edge processing save up to 70% of system power consumption and 45% of PCB area, it’s claimed. In addition, the number of pin connections can be reduced by 50%, thereby saving external connections. And the package height is 14% less than preceding ST MEMS inertial sensors.
The LSM6DSV16BX comes with many software examples, available on ST MEMS’ FSM and MLC GitHub repositories. These include pick-up gesture detection to automatically turn on some device’s services, in-ear and out-of-ear detection in TWS headsets, head gestures for 3D sound in headphones, and many more. To save developer time, without starting from scratch, pre-integrated application examples are available in the X-CUBE-MEMS1 package.
The LSM6DSV16BX is in production now, available in a 2.5- × 3.0- × 0.74-mm VFLGA package, priced from $3.95 for orders of 1,000 pieces.