Patent ID: 7463016

Claim:
A current sensor comprising: a conductor line that includes: a pair of parallel portions extending in parallel with each other separated by a first distance therebetween, each of the parallel portions having a same and uniform cross-sectional area orthogonal to an extending direction of each of the parallel portions; a connecting portion connecting one end of one of the parallel portions and one end of the other of the parallel portions; and a pair of terminal portions each connected to the other end of each of the parallel portions, while extending to face each other separated by a second distance therebetween, the second distance being wider than the first distance, the terminal portions each having a larger cross-sectional area orthogonal to an extending direction of each of the terminal portions than the cross-sectional area of each of the parallel portions orthogonal to the extending direction of each of the parallel portions; a magnetic sensor in which resistance value changes according to a current magnetic field produced by a current to be detected flowing through the conductor line, the magnetic sensor including first and second magnetoresistive elements each disposed along each of the parallel portions so that the resistance value of one of the magnetoresistive elements changes in a direction opposite to that of the other of the magnetoresistive elements according to the current maanetic field produced by the current to be detected which flows through the conductor line; first and second constant current sources supplying constant currents of a common value to the first and the second magnetoresistive elements respectively; and a differential detector detecting a difference in voltage drops caused in each of the first and the second magnetoresistive elements by the constant currents, wherein the current to be detected is detected on the basis of the difference in voltage drops.