GMR Revolution Sensors for Automobiles

We have developed a new series of revolution sensors using Giant Magnetoresistive (GMR) elements. We call these GMR revolution sensors. In automotive applications, revolution sensors have traditionally utilized Hall effect and anisotropic magnetoresistive (AMR) elements. Recently, more sensitive revolution sensors are necessary for improved control of engines, braking systems and automatic transmissions. Since GMR elements have one order higher MR ratio than AMR elements, GMR revolution sensors are much more sensitive. Furthermore, GMR elements have been integrated with circuits on Si substrates. This integration simplify the assembly process and increases the reliability of the GMR revolution sensors. This paper discusses the superiority of GMR sensing elements over Hall and AMR elements. This paper also reports the characteristic results of the GMR sensor.