Patent ID: 7375516

Claim:
A magnetic field detector having a reference magnetoresistive element and a magnetic field detecting magnetoresistive element, the reference magnetoresistive element and the magnetic field detecting magnetoresistive element each having a stack structure including: an antiferromagnetic layer, a first layer of a ferromagnetic material with the direction of magnetization fixed by the antiferromagnetic layer, a nonmagnetic layer, and a second layer of a ferromagnetic material with the direction of magnetization adapted to be changed by an external magnetic field, characterized in that the reference magnetoresistive element is such that the direction of magnetization of the first layer and the direction of magnetization of the second layer in the nonmagnetic field are parallel or antiparallel to each other, and the magnetic field detecting magnetoresistive element is such that the direction of magnetization of the first layer and the direction of magnetization of the second layer in the nonmagnetic field are different from each other.