Magnetic field sensor and related techniques that provide an angle correction module

摘要

A magnetic field sensor provides an angle error value to correct errors of the magnetic field sensor. The angle error value is a function of temperature and magnetic field strength and is used to correct a measured magnetic field angle. Associated methods are also described.

主权项

1. A magnetic field sensor, comprising:
a plurality of magnetic field sensing elements, wherein each one of the plurality of magnetic field sensing elements is configured to generate a respective x-y output signal responsive to a magnetic field in an x-y plane; an angle processing circuit coupled to receive the x-y output signals and configured to generate an uncorrected x-y angle value representative of an angle of the magnetic field in an x-y plane, wherein the uncorrected x-y angle value comprises a first angle error; a temperature sensor configured to generate a temperature signal representative of a temperature; an angle error correction module coupled to the angle processing circuit and the temperature sensor and configured to generate, in response to a measured magnetic field signal and the temperature signal, an x-y angle error value indicative of an error in the uncorrected x-y angle value and comprising a ratio of a nominal magnetic field strength to a measured magnetic field strength; a coefficient table configured to store a plurality of correction coefficients for use by the angle error correction module, wherein the plurality of correction coefficients comprises a plurality of magnitudes and phases of one or more harmonics of the first angle error; and a combining module configured to combine the uncorrected x-y angle value with the x-y angle error value to generate a corrected x-y angle value having a second angle error smaller than the first angle error.