April 20, 2010
Asahi Kasei Microdevices Corp.

New 3-axis electronic compass for portable appliances
- One-chip system with Si monolithic Hall elements for size
reduction to less than half that of equivalent AKM product -
Asahi Kasei Microdevices (AKM), the Asahi Kasei Group's core operating company for electronic components, has rolled out its latest 3-axis electronic compass for portable appliances, the AK8975B. With a package size less than half as large as AKM's previous equivalent product, the AK8975B continues the AKM tradition of leadership in electronic compass technology.

The world's first 3-axis electronic compass for portable appliances, the AK8970, was launched by AKM in 2003. Since then, AKM's 3-axis electronic compass products have been adopted in more than 80 models of mobile phone, establishing a position as the global de facto standard.

AKM believes there are two key factors behind the successful achievement of this wide adoption of its 3-axis electronic compass products. The first of these is AKM's ongoing development of leading-edge technology for successive product improvements. Although the AK8970 was the world's smallest electronic compass at the time of its launch in 2003, AKM continued to lead the development of electronic compass products, providing customers with a road map of forthcoming advancements for smaller and thinner product size. The second factor is AKM's provision of an algorithm for the automatic compensation for magnetic offset caused by magnetic or ferrous components inside a handset, which frees the consumer from the hassle of performing calibration.

Throughout its developments, AKM has consistently moved beyond the conventional concept of simply manufacturing devices. Not content to just focus on the sensitivity and accuracy of the magnetic sensor function, AKM has sought to improve the usability of its devices from the standpoint of the user's experience. It is from this perspective that, together with its hardware, AKM supplies software that enables reliable azimuth information to be obtained at all times. This concept has earned wide recognition throughout the industry as the key to making an electronic compass easy to use.
Distinguishing features of the AK8975B are as follows:
1) AKM's exceptional one-chip electronic compass architecture with a 3-axis magnetic sensor comprising Si monolithic Hall elements and a magnetic concentrator.
  While mass-producing 3-axis electronic compasses in a multi-chip module configuration from 2003 to 2006, AKM realized that not only does this configuration present difficulties for further miniaturization, but it also imposes an inherent performance drawback as even slight orthogonal errors during module assembly have a critical effect. Maintaining orthogonality between axes is crucial in multi-axis sensor devices such as the electronic compass, influencing overall product performance even more than the performance of each individual sensor element does. AKM therefore made a transition to Si monolithic electronic compass products which require no module assembly process and are thus inherently free from orthogonal imprecision.
2) Ball grid array (BGA) chip-size package (CSP) with size reduced to less than half that of AKM's previous BGA product.
  AKM's current electronic compass, the AK8973 series, includes products with two different CSP packaging options: AK8973B with BGA packaging, and AK8973S with low-profile packaging. With an even smaller BGA package size, the new AK8975B provides both low profile and easy mountability-combining the characteristics of the two previous products-while affording enhanced productivity by unifying production on a single packaging conformation.
3) Software compatibility with previous AKM electronic compass products, enabling customers to utilize existing software assets, including AKM's patented algorithm for the automatic compensation for magnetic offset.
  Prior to launching commercial production of the world's first 3-axis electronic compass, AKM applied for patents on a function to automatically compensate for magnetic offset. The software library for this function has been provided ever since to customers of AKM's electronic compass products together with the hardware.

This proven software to automatically compensate for magnetic offset can be used with the new AK8975B just as with AKM's previous electronic compass products. This technology not only enables superior productivity, as electronic compasses installed in portable appliances need no adjustment for magnetic offset before shipment, but also frees the consumer from the hassle of performing calibration in response to changes in magnetic offset during product use.
Main applications
  Applications include pedestrian navigation and augmented reality (AR) systems on mobile phones and PDAs.
Basic specifications of the AK8975B
Packaging: 14-pin CSP package, 2.0 mm 2.0 mm 0.65 mm
Measurement range: 1200 T
Resolution: 0.3 T (13-bit data output)
Interface: Two-wire I2C or four-wire SPI (selectable)
Patented AKM technology
  Patents which have been granted to AKM related to the function of automatic compensation for magnetic offset include the following.
Japan: 4391416, 4448957, 4151784, 4151785, 4073715
USA: 7653507, 7376527, 7340362, 7177779
China: ZL200480038521.0, ZL03815813.2
Korea: 10-0939158, 10-0944308
Germany: 602004024333.7
UK: 1698857
  Furthermore, in March 2010, AKM acquired a patent (Japan: 4177032) related to technology for the configuration of multi-axis magnetic sensors from Wacoh Corp. This technology will enable AKM to develop multi-axis magnetic sensors with different structures in addition to its existing products, providing a valuable complement to AKM's products lineup and technology portfolio. With such technology assets, particularly various patented technologies for Si monolithic multi-axis magnetic sensor configuration, AKM will extend its established market leadership in the field of electronic compasses.
  AKM will continue to enhance the market competitiveness of its multi-axis magnetic sensor products, including the electronic compass, enforcing the rights of this newly acquired patent in addition to its other patents, while utilizing its range of patent-pending technologies technical know-how.


Adobe Readeris required to view these PDF files.

page top