infineon has already started applying this effect to measure the steering angle of a car and has become the first semiconductor supplier in the world to start mass production of an integrated giant magneto-impedance sensor (iGMR). Infineon‘s sensor with extraordinary accuracy measuring 0° to 360° integrates two GMR full bridges, a temperature sensor, two A/D converters, several voltage regulators, additional filters and for continuous monitoring The internal mechanisms by which these devices operate.

Infineon‘s sensor chip TLE 5010 provides two digital angle components: a sine function and a cosine function. An accurate angle signal can be calculated by connecting the sensor to an eight-bit MCU via an SPI interface. Transmitting digital data between the sensor and the MCU means that susceptibility to interference is reduced, and an integrated temperature sensor for compensation ensures highly accurate angles over a wide temperature range of -40 °C to +150 °C.

The GMR effect is based on the principle of impedance change produced by a magnetic field between multiple metal films with a thickness of several nanometers. Simply put, the film carries a fixed reference layer with a stable magnetization direction (reference direction) and a sensor layer whose magnetization direction follows the external magnetic field, like the needle of a compass. The GMR effect is created by separating the sensor and reference layers by a copper layer only a few atoms thick.

The reactance of such films varies according to the magnetic field used and the angle between the sensor reference layers. Infineon has successfully integrated this layer of necessary precision into standard CMOS semiconductor production processes.