A Novel Orthogonally Activated Double-hall Device

Abstract

Abstract The offset and its temperature drift are almost fully compensated in a novel design orthogonally activated silicon double-Hall device. The proposed sensor consist two functionally integrated three-contact Hall elements sharing the same transducer region with rectangular shape and common central electrode. Two pairs equal in value but opposites in direction supply currents are formed by the structure symmetry and using equal resistors. In an orthogonal magnetic field, the Lorentz force deviate the pairs of current paths in opposite directions. The Hall elements have almost equal offsets, the offset temperature drifts are perfectly matched and Hall voltages are equal in value but of opposite sign. The output signal is given by subtraction of two output voltages using a circuitry with three op-amps. The residual offset was about 140 times lower than the individual ones in the range – 10 °C ≤ T ≤ 80 °C and the magnetic-field depended signal is almost doubled.