Process-independent integrated sensitivity calibration of 3D hall sensors

An excitation coil arrangement for 3D Hall sensors is shown allowing the integrated calibration of all three orthogonal sensitivities independent of process tolerances. Because of process tolerances the spacing between an integrated excitation wire and the vertical Hall sensors cannot be known exactly neither can the magnetic flux density of the excitation wire be calculated. By using a special arrangement of integrated excitation wires in combination with a special algorithm, the effective distance between the excitation coil and the sensor can be calculated. With this measured effective distance the magnetic flux at the location of the sensor can now be calculated with a high degree of accuracy and thus the sensitivity can be determined. Now in a production test the sensitivity can be measured without external excitation coils which will save time and money.