Single-chip, nine-axis INU targets consumer devices
R Colin Johnson, EE Times -- EDN, February 2, 2012
A new nine-axis INU (inertial navigation unit) from Invensense combines an accelerometer, a gyroscope, and a magnetometer in a single 3-D chip stack for use in consumer devices, such as smartphones, touchscreen tablets, gaming controllers, and wearable motion-tracking modules. The module eliminates the errors that accumulate when using separate inertial sensors from different vendors, according to Steve Nasiri, chief executive officer and founder of Invensense. “The MPU-9150 motion-tracking module will be a boon to any consumer motion-processing application, from location-based services to gesture recognition,” he says.
The product combines the
MPU-6050 gyroscope chip
with the AKM8975 magnetometer
from AKM (Asahi Kasei
Microdevices) Corp. The 3-D
chip stack includes an ASIC
containing the electronics and
motion-processing accelerator
on the bottom, with the
MEMS die for the accelerometer/gyroscope in the middle,
and is wire-bonded to AKM’s magenetometer on top. The
accelerometer, the gyroscope,
and the magnetometer each
have three axes, and the module
comes with smart sensor-fusion
acceleration in a 4×4×1-mm LGA package.“Traditionally, designers have specified different suppliers for their accelerometers, gyroscopes, and magnetometers,” says Nasiri. With the new device, he explains, OEMs can choose one vendor’s precalibrated product, saving time to market; in one package to save PCB space; and with built-in sensor-fusion algorithms to ensure optimal performance.
Invensense MotionFusion firmware offers a turnkey product for OEMs, and its Motion-Apps software platform, which comes with the product, simplifies the system-integration task for popular operating systems, including Google’s Android. AKM’s proven magnetometer finds use as a digital compass in everything from Apple’s iPhone/iPad to Samsung’s Galaxy S/Tab. Samples are available now, and volume production is planned by the end of this quarter.
Invensense
