Patent ID: 8760158

Claim:
A current sensor comprising: a conductor through which a current to be measured flows; and a magnetic detecting bridge circuit formed of four magneto-resistance effect elements with a resistance value varied by application of an induced magnetic field from the current to be measured, the four magneto-resistance effect elements having a same resistance change rate, each of the four magneto-resistance effect elements having a laminated structure including: a self-pinned type ferromagnetic fixed layer formed of a first ferromagnetic film and a second ferromagnetic film anti-ferromagnetically coupled to each other; a nonmagnetic intermediate layer; and a soft magnetic free layer, wherein the laminated structure does not include any layer made of antiferromangnetic material, wherein the magneto detecting bridge circuit has an output between two of the four magneto-resistance effect elements, magnetization directions of the ferromagnetic fixed layers of the two magneto-resistance effect elements being different from each other by 180°, wherein the magnetic detecting bridge circuit has a wiring symmetrical to a power supply point, wherein the magnetic detecting bridge circuit measures the current to be measured by the outputs of the four magneto-resistance effect elements which are in proportion to the induced magnetic field, wherein each of the magneto-resistance effect elements has a meandering shape including a plurality of stripes, each of the plurality of stripes being perpendicular to the induced magnetic field extended from the conductor, and wherein the magnetization direction, which is a pin-direction, of each of the ferromagnetic fixed layers is perpendicular to the stripes in each of the magneto-resistance effect elements.