CES 2024 - Ultra small MEMS accelerometers for wearables and hearables

With space at a premium in hearables, smartwatches and other portable consumer products, all components must be as small as possible.

However, with OEMs also demanding plug-and-play step-counters and other sensors with built-in features that enable easy implementation without detailed application knowledge Bosch Sensortec has announced the BMA530 and BMA580, the world's smallest MEMS accelerometers.

Both of these devices include built-in features making them easy to design with. BMA530 tracks activities with its step counter and is especially suitable for wearables, and BMA580 targets hearables with voice activity detection.

Compared to Bosch's current generation accelerometer (BMA253), the BMA530 and BMA580 have a 76 percent smaller footprint and have been reduced in height from 0.95 mm to 0.55 mm. This size reduction is achieved with a new Wafer Level Chip Scale Package (WLCSP).

The small size of the accelerometers makes them easy to place on a PCB, and their integrated features make them easy for design engineers to integrate into their portable products.

The BMA580 provides voice activity detection and an advanced feature set for hearable devices.

Typically, microphones in hearables consume a lot of power because they need to be always-on to listen for voice activity. Instead, the BMA580 uses bone conduction to detect the vibration of the user’s voice and then wakes the microphone from sleep – for an overall power saving.

The BMA580 enables user interaction with a hearable in response to the user tapping the device, for example to answer or end a call. The sensor’s software includes an algorithm that can distinguish between single, double and triple taps.

In addition to wearables, the new BMA530 acceleration sensor is suitable for gesture recognition in toys, fall detection in laptops and other devices, and power management functions such as putting a smartphone to sleep when it is not moved.

These accelerometers offer multiple power modes and automatically switch from low-power to high-power modes to extend battery life. They offer a flexible set of connectivity options, including an I3C interface.

The new acceleration sensors from Bosch Sensortec can be ordered from distribution partners from Q1 2024 onwards.