Patent ID: 8269492

Claim:
A magnetic balance type current sensor comprising: a pair of sensor elements, each sensor element having a magnetoresistive effect element, the resistance value of which changes due to application of an induction magnetic field from a measured current and which has a pinned magnetic layer, a pinned resistive element, and a feedback coil arranged in the vicinity of the magnetoresistive effect element to generate a cancel magnetic field canceling the induction magnetic field, the pair of sensor elements constituting a bridge circuit for magnetic field detection including two outputs, which generate a voltage difference according to the induction magnetic field, wherein the measured current is measured on the basis of a current which flows in the feedback coil when electrical conduction is provided to the feedback coil by the voltage difference and an equilibrium state is reached in which the induction magnetic field and the cancel magnetic field cancel each other, the sensor elements are arranged at positions with equal magnetic field from the measured current, the magnetization direction of the pinned magnetic layer in the magnetoresistive effect element of one sensor element is aligned in a forward direction with respect to the magnetic field formed by the measured current, and the magnetization direction of the pinned magnetic layer in the magnetoresistive effect element of the other sensor element is aligned in a reverse direction with respect to the magnetic field formed by the measured current.