Bosch Sensortec Introduces Geomagnetic Sensor For Mobile Applications

“With the BMM150 Bosch Sensortec has developed a leading-edge low power and high performance magnetic field sensor. Together with our BMI055 – an inertial measurement unit consisting of gyroscopes and accelerometers – and our sensor data fusion software, it can be easily combined to a 9 Degrees of Freedom solution”, says Leopold Beer, Marketing Director of Bosch Sensortec. “We are the only MEMS supplier developing all inertial and magnetic sensing technologies plus barometric pressure sensors in-house. Figuratively, our sensor data fusion software is the fifth MEMS component. The intimate sensor know-how is the key to high performance solutions and intelligent power management.”

Building block for 9DoF sensor solutions

In combination with triaxial acceleration sensor and gyroscope from Bosch Sensortec, the device is ideally suited for inertial sensing in smartphones, tablet computers, navigation systems or remote controls. By means of sensor data fusion software, also available from Bosch Sensortec, the 9 Degrees of Freedom solution determines the absolute spatial orientation as well as motion vectors with high accuracy and dynamics. Augmented Reality and indoor navigation applications running on smartphones and other handheld devices require the spatial orientation provided by such sensors as input data. Here, the geomagnetic sensor plays an important role contributing the absolute orientation with respect to magnetic north. The very low power consumption is one of the key benefits of the FlipCore technology and translates into longer battery life.

Flexible design options through small form factor

The extremely small form factor of the new sensor offers multiple benefits for designers of portable devices. The available space in mobile phones is increasingly used for displays and batteries, since these components are becoming larger with every generation. Therefore the size of the printed circuit boards needs to be reduced constantly. The BMM150 helps designers to save valuable PCB area. Another benefit of the small footprint results from the requirement to move geomagnetic sensors as far away as possible from ferromagnetic parts as e.g. loudspeakers, screws, or camera modules to avoid distortion of the sensor. The extraordinarily compact size of the BMM150 along with its high effective measurement range of ±1300 µT gives designers the maximum flexibility in positioning the sensor within the device. Due to its height of only 0.6 mm, the sensor can easily be placed in the edges of the casing or on stacked PCBs.

Feature sets for easy design-in

The BMM150 features an on-chip interrupt controller which sends signals to the host controller when the sensor data have changed or when customer-defined threshold values are exceeded. In addition, the BMM150 offers four programmable power presets which enable designers to optimize the device for their specific requirements. Minimum power consumption of 170µA at a data rate of 10Hz can be achieved in the low power preset. The sensor can also be operated in the high accuracy preset – resulting in 0.3µT RMS-noise – for applications requiring high precision measurement.