Patent ID: 8593134
Filing Date: 2013-11-26
Classification: B82Y,G01R

Abstract:
1. A current sensor comprising: first to fourth magneto-resistive elements extending together in one direction along a conductor and configuring a bridge circuit, the first and third magneto-resistive elements having resistance values which change together in one increasing/decreasing direction in response to the induced magnetic field generated by a current-to-be-detected flowing in the conductor, whereas the second and fourth magneto-resistive elements having resistance values which change together in other increasing/decreasing direction opposite to that of the first and third magneto-resistive elements in response to the induced magnetic field, the bridge circuit being so configured that one end of the first magneto-resistive element is connected to one end of the second magneto-resistive element at a first junction, one end of the third magneto-resistive element is connected to one end of the fourth magneto-resistive element at a second junction, other end of the first magneto-resistive element is connected to other end of the fourth magneto-resistive element at a third junction, and other end of the second magneto-resistive element is connected to other end of the third magneto-resistive element at a fourth junction; and a compensation current line including one or more first line portions corresponding to the first magneto-resistive element, one or more second line portions corresponding to the second magneto-resistive element, one or more third line portions corresponding to the third magneto-resistive element, and one or more fourth line portions corresponding to the fourth magneto-resistive element, each line portion having a width smaller than that of corresponding one of the first to fourth magneto-resistive elements and extending in a direction same as the extending direction of the first to fourth magneto-resistive elements to overlap corresponding one of the first to fourth magneto-resistive elements, the compensation current line allowing a compensation current, which is generated in accordance with a potential difference between the first and second junctions in response to application of voltage between the third and fourth junctions, to flow therein to generate a compensation magnetic field which is directed, at each of the first to fourth magneto-resistive elements, to a direction opposite to that of the induced magnetic field and is applied to the first to fourth magneto-resistive elements, wherein the current-to-be-detected is detected based on the compensation current.