Patent ID: 7589612

Claim:
A current sensor for detecting a current in the range of 10 mA to 50 mA, comprising: a first conductor disposed in a first layer, the first conductor having a first extended portion extending in a first direction and being supplied with the current; and a first magnetoresistive element disposed in a second layer in an area corresponding to the first extended portion, a resistance value of the first magnetoresistive element varying according to a first magnetic field generated by the current flowing through the first extended portion, the current sensor satisfying the following conditional expressions (1) and (2): 0.4 μm≦D1≦1.0 μm (1) 0.4 μm 2 ≦S1≦3.0 μm 2 (2) where D 1 is a distance between a first extended portion and a first magnetoresistive element; and S 1 is an area of a cross-section orthogonal to a first direction in the first extended portion.