A system comprises first and second Hall-effect sensors and an amplifier. The first Hall-effect sensor has a first bias current direction parallel to a first direction, a pair of first bias input terminals spaced along the first direction, and a pair of first sense output terminals spaced along an orthogonal second direction. The second Hall-effect sensor has a second bias current direction parallel to the second direction, a pair of second bias input terminals spaced along the second direction, and a pair of second sense output terminals connected out of phase with the first sense terminals. The amplifier has a pair of amplifier input terminals coupled to the first and second sense terminals.