Bosch Claims Smallest MEMS Accelerometers for Hearables and Wearables
The new MEMS devices have a 76% smaller footprint than Bosch’s current generation of acceleration sensors.
While plenty of newsworthy headlines emerged from CES this year, one that caught the attention of the hardware design world came from Bosch. The company announced the release of two new MEMS accelerometers—devices it claims are the world’s smallest for hearable and wearable applications.
The BMA530 and BMA580 offer fall detection, gesture and tap recognition, and power-saving modes.
BMA530: A Power-Saving, Sensitive Wearable Sensor
Measuring just 1.2 x 0.8 x 0.55 mm³, the BMA530 and BMA580 are the world’s smallest MEMS accelerometers, according to Bosch. The BMA530 is a low-power MEMS-based acceleration sensor designed specifically for compact devices such as wearables and toys. It features a 16-bit digital resolution, a measurement range of ±2 to ±16 g, and data rates ranging from approximately 1.56 Hz to 6.4 kHz.
Both acceleration sensors are 1.2 x 0.8 x 0.55 mm³.
Despite its small size, the device is also accurate, with a sensitivity error within 1%, noise density as low as 120 µg/√Hz, and a temperature coefficient offset (TCO) at ±0.5 mg/K, ensuring consistent performance over its lifespan. This makes it useful for step counting in wearables. In terms of power consumption, the device requires only 125 µA in high-performance continuous measurement mode, 18 µA in low-power mode at 100 Hz, and 4.75 µA in suspend mode with data retention.
In addition to offering motion detection in wearables, the acceleration sensor can put mobile devices in sleep mode when they are not moved, recognize gestures in toys, and detect falls in laptops and other devices.
BMA580: The First Hearable Sensor With Bone Conduction
The BMA580 includes features particularly designed for hearable devices, such as voice activity detection through bone conduction. Hearables typically use always-on microphones to listen for voice activity, consuming high amounts of power in the process. In contrast, the BMA580's bone conduction feature detects a user's voice vibration to wake the microphone from sleep only when needed. The acceleration sensor also helps users better interact with their hearable by detecting taps to the device to answer or end calls or start and stop music. Using internal software, the sensor can accurately interpret single, double, and triple taps.
The BMA580 offers a 16-bit digital resolution and a similar measurement range and output data rate as the BMA530. The sensitivity error and TCO are even lower at 0.5% and ±0.2 mg/K, respectively, while the noise density is the same as the BMA530. Both the BMA530 and BMA580 support a range of connectivity options, including an I3C interface.
Shaping the Future of Wearables and Hearables
Bosch claims that both the BMA530 and BMA580 may have a significant impact on the future of wearable and hearable technology due to their unique combination of size, precision, and power efficiency. Thanks to these features, the new accelerometers may give rise to wearables and hearables that are not only more compact and aesthetically pleasing but also more functional and energy-efficient.
All images (modified) used courtesy of Bosch.
