Bosch unveils tiny MEMS accelerometers

Unveiled at CES 2024, Bosch Sensortec has introduced the BMA530 and BMA580 MEMS accelerometers for wearable and hearable devices. Claimed as the smallest in the industry, both devices measure 1.2 × 0.9 × 0.55 mm and include built-in features that make them easy to design into portable products. The BMA530 tracks activities with its step counter, targeting wearables, while the BMA580 is suited for hearables with voice activity detection.

(Source: Bosch Sensortec)

These new MEMS accelerometers address two key issues in the portable consumer market: the need for smaller components and sensors with built-in features that make them easy to implement without deep application knowledge. 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 thanks to their wafer level chip scale package (WLCSP).

The acceleration sensors also offer multiple power modes and automatically switch from low-power to high-power modes to extend battery life. Current consumption ratings are 125 µA (high perf, continuous measurement), 18 µA (low power@ 100 Hz) and 4.75 µA (suspend mode, data retention). A set of connectivity options are offered, including an I3C interface.

The BMA530 acceleration sensor includes integrated functions like step-counter and generic interrupts. Key specs include measurement ranges of ±2, ±4, ±8 and ±16 g; 1% sensitivity error and 16-bit digital resolution. In addition to wearables, the BMA530 also can be used for gesture recognition in toys, fall detection in laptops and other devices, and power management functions.

The BMA580 features voice activity detection, an advanced feature set for hearable devices and low power consumption. It enables user interaction with a hearable in response to the user tapping the device, for example to answer or end a call. The software includes an algorithm that can distinguish between single, double and triple taps. Key specs include 16-bit digital resolution, 0.5% sensitivity error and measurement ranges of ±2, ±4, ±8 ±16 g.

The acceleration sensor also uses bone conduction to detect the vibration of the user’s voice and then wakes the microphone from sleep, which delivers a power savings compared with typical microphones in hearables that consume a lot of power because they need to be always-on to listen for voice activity, according to Bosch Sensortec. It is the only sensor that combines bone conduction in this size, the company said.

The new acceleration sensors are available through the company’s distribution partners, starting in the first quarter of 2024. The devices will be showcased for the first time at CES at the Bosch booth#17207.