Alps Electric Releases Geomagnetic Sensors, Increasing Detection Accuracy by 40%

Figure: Geomagnetic sensor "HSCDTD004A" with about 30% lower noise than the company's original product

Japan Alps Electric issued on May 26, 2011, a geomagnetic sensor "HSCDTD004A" whose position detection accuracy is 40% higher than that of the original product (Fig. 1). It is mainly used for electronic compasses equipped with smart phones and tablet terminals. Mass production began in May 2011 and is scheduled to reach a monthly production of 3 million units in October 2011.

Compared with the original product released by the company in December 2009, HSCDTD004A reduced the amount of noise by about 30%. "There is no change in the structure of the components, but the details have been improved. In addition, the output of the sensor has been increased" (the company). Thus, while improving the accuracy of azimuth detection, the measurement time is also shortened. In addition, the magnetic field measurement range of ±0.6mT for the original product was expanded to ±1.2mT. The sensor element uses a magnetoresistive (MR) element and utilizes the property that the resistance value varies with the strength of the magnetic field.

The HSCDTD004A increases the performance while controlling the consumption current to be less than 200μA, which is the same as the original product. The external dimensions are 2.5mm x 2.5mm x 0.7mm, which is also the same as the original product. The output resolution is 0.3μT.

In addition to the Inter-Integrated Circuit (I2C), the interface also supports SPI (Serial Peripheral Interface). The operating temperature range is -30 to +85°C. For the power supply voltage, the analog part is 2.4 to 3.6V and the digital part is 1.7 to 3.6V.

Applications include electronic compasses equipped with smartphones and tablet terminals. Recently, the number of GPS-equipped models in digital cameras has also increased, and models using electronic compasses have begun to appear. With the electronic compass, the shooting direction can be detected and recorded. In addition, it is also planned for game and head-mounted display (HMD) motion control.