Patent ID: 6064202
Filing Date: 2000-05-16
Classification: G01R

Abstract:
A method of reducing the offset of a Hall device having a generally circular conductive area and at least four electrical contacts connected to the periphery of the circular conductive area in pairs of opposite contacts, the contact pairs being angularly separated from each other by equal spatial angles, or having an arrangement of conductive area and contacts derived by conformal mapping from said arrangement with the circular conductive area, the method comprisingapplying to all contact pairs continuously or stepwise alternating currents of a preselected frequency and with phase shifts corresponding to the angles separating the contact pairs from each other to create a bias current rotating in the conductive area continuously or in angular steps smaller than the angles separating the contact pairs,measuring voltage differences across the conductive area in directions perpendicular to the momentary directions of the bias current in succession for a plurality of evenly spaced bias current directions greater than the number of contacts, andaveraging the voltage differences measured during at least one rotation period of the bias current.