Inertial Measurement Unit has 9-axis measurement, under 1mA current

November 13, 2014 // By Graham Prophet
Bosch Sensortec‘s BMI160 Inertial Measurement Unit (IMU) integrates a 16-bit 3-axis, low-g accelerometer and an ultra-low power 3-axis gyroscope into a single package. It has been designed specifically for high precision, always-on 6-axis and 9-axis applications in smart phones, tablets, wearable devices, remote controls, game controllers, headmounted devices and toys.

The BMI160 is available in a 14-pin 2.5 × 3.0 × 0.8 mm LGA package. When the accelerometer and gyroscope are in full operation mode, the typical current consumption is 950μA, claimed as half that of prior devices. Applications such as immersive gaming, augmented reality and the emerging 3D indoor scanning applications must deliver precise, real-time user experiences. The BMI160 achieves this by synchronising the inertial accelerometer and gyroscope sensor data precisely with external geomagnetic sensor data, and is suited for applications requiring exact, low latency low power 9-axis sensor data fusion.

“Current battery limitations in devices such as smart watches, augmented reality glasses and wearable devices are restricting the adoption of more sophisticated applications which need to be continuously powered,” says Jeanne Forget, Marketing Director of Bosch Sensortec.

Additional sensors from the Bosch Sensortec family, such as geomagnetic (BMM series) or pressure sensors (BMP series), can be connected as slaves via a secondary I²C interface. In this configuration, the BMI160 controls data acquisition of the external sensor with all sensor data being stored in the built-in FIFO. With the secondary interface configured as high speed SPI interface and connected to camera module, BMI160 also supports optical image stabilisation (OIS).

The built-in power management unit (PMU) can be configured to further lower power consumption by automatically sending the gyroscope temporarily into fast start-up mode, then wake-up using the any-motion interrupt of the accelerometer. When connected to a geomagnetic sensor, the BMI160 can trigger a read-out of the magnetometer sensor data without host processor intervention. Longer host controller sleep cycles reduce power consumption at the system level. The integrated FIFO supports low power applications and prevents data loss in non-real-time systems. The FIFO architecture allows dynamic reallocation of FIFO space for accelerometer, gyroscope and external sensors respectively.

The BMI160 features an on-chip interrupt engine enabling low-power motion-based gesture recognition and context awareness. Interrupts issued in a power efficient manner include: any-