Kionix Micro-Amp Gyro was published in the Dempa newspaper on May 9th in Japan.

See it at Sensor's Expo: booth 901

Contributing Articles

Special Features: Sensor technology
Kionix Micro-Amp Gyro – Unlocking New Markets for Inertial Sensors

Consumer electronics devices continue to develop, becoming increasingly intelligent by incorporating a variety of sensors to enable greater functionality in the form of applications such as gesture recognition, step-counting and activity monitoring, and indoor navigation. Product designers face constant pressure to incorporate this greater functionality while simultaneously reducing power draw and size. As a result, gyroscopic functionality is often out of reach for many mobile products due to the gyro's notoriously high current draw. In order to give customers the functionality that they desire, without prohibitive power costs, Kionix has developed the KMX61G – the world's first micro-amp magnetic gyro with integrated sensor fusion, a breakthrough product that reduces current draw by up to 90% compared to traditional gyros. (See Picture-1)

Packaged KMX61G
[Picture-1] Packaged KMX61G

The KMX61G is designed to enable a full 9-axis solution with unique capabilities and lower current consumption than any other solution utilizing a traditional gyro. This 6-axis magnetometer-accelerometer device consists of a tri-axial GMI magnetometer and a tri-axial accelerometer coupled with an ASIC and packaged together in a single 3x3x0.9mm, 16-pin LGA plastic package. Enhanced with Kionix's proprietary sensor fusion software and auto-calibration algorithms, the high-performance KMX61G delivers highly accurate emulated tri-axial gyro outputs.

Most importantly, the KMX61G provides extremely low current draw, requiring only 5 µA in standby and a maximum of 550µA in full operating mode (both magnetometer and accelerometer), compared to the 5mA required for traditional gyro-based 9-axis solutions. As a result, this innovative device will allow product designers to incorporate gyro functionality in products with stringent power constraints that in the past were restricted from including a gyro due to its high power consumption.

How does the KMX61G work?

It takes a very low noise accelerometer and a very sensitive and low noise magnetometer to enable a solution such as this. In addition, it requires very sophisticated Sensor Fusion software to combine the two in a way that produces a gyroscopic output. (See Figure-1)

Sensor Fusion Diagram
[Figure-1] Sensor Fusion Diagram

The accelerometer uses Kionix's XAC sense element, the most advanced sense element ever made by Kionix. It has very low noise and is extremely stable over temperature.

The magnetometer is the other crucial component. The magnetometer in the KMX61G uses GMI technology to achieve sensitivity and noise performance unlike anything else available in the consumer market. (See Figure-2)

Magnetic Gyro Solution
[Figure-2] Magnetic Gyro Solution

The KMX61G also features a 512 byte FIFO buffer with watermarking, 14-bit digital outputs accessed through I2C communication, and a total magnetometer measurement range of ±1200µT. The ASIC is realized in standard 0.18um CMOS technology and features flexible a user-programmable, ±2g/±4g/±8g full-scale range for the accelerometer. The product operates from 1.8V to 3.3V and at a temperature range of -40℃ to 85℃.

Other features include an embedded temperature sensor, embedded motion wake-up and back-to-sleep functions, a programmable interrupt engine, and an accelerometer self-test function.

Power and Space Savings for Mobile Consumer Applications

The KMX61G provides significant power and space savings over the currently available 9-axis solutions, while providing a comparable level of performance that allows the KMX61G to act as a replacement for traditional 9-axis solutions in the majority of mobile phone, tablet and consumer electronics applications. The KMX61G is also extremely beneficial in mobile devices that run on small or button-type batteries where traditional gyros are just not an option due to current drain.

Kionix, a major supplier of motion sensing technologies to the mobile phone and CE industries, was able to draw on its engineering resources and expertise to develop the KMX61G, a breakthrough product that adds to the Company's reputation for innovative product design. Now, with the KMX61G, these products can incorporate gyro outputs and a full 9-axis solution while still meeting their power consumption and battery life requirements. This opens up a range of new applications in the mobile consumer electronics market as well as in many others.

The KMX61G – The way of the future.

Kionix is committed to working jointly with Rohm and Lapis Semiconductors and to provide its valued global customers with the best sensor solutions in the industry.