Patent ID: 11892325
Assignee: MELEXIS TECHNOLOGIES NV
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method of determining a linear or angular position of a magnetic sensor device relative to a magnetic source, or vice versa; the magnetic sensor device comprising:
a first, a second, a third and a fourth magnetic sensor element;
a first, second, third and fourth biasing source for biasing said sensor elements;
a first, second, third and fourth amplifier for amplifying a signal originating from said sensor elements;
at least one analog-to-digital converter for digitizing signals originating from said amplifiers;
one or both of a temperature sensor and a differential stress measurements circuit;
a digital processing circuit connected downstream of the analog-to-digital convertor;
the method comprising the steps of:
obtaining one or both of a temperature value and a differential stress value;
a) determining a first magnetic field gradient based on signals obtained from the first and the third magnetic sensor element;
b) determining a second magnetic field gradient based on signals obtained from the second and the fourth magnetic sensor element;
c) calculating a ratio of the first and the second magnetic field gradient;
d) determining said linear or angular position based on said ratio;

wherein:
step a) comprises: adjusting the third biasing source and/or adjusting a signal path comprising the third amplifier using a first predefined function of temperature and/or differential stress, to match a signal path containing the third sensor element to a signal path containing the first sensor element; and
step b) comprises: adjusting the fourth biasing source and/or adjusting a signal path comprising the fourth amplifier using a second predefined function of temperature and/or differential stress, different from the first predefined function to match a signal path containing the fourth sensor element to a signal path containing the second sensor element;
step d) further comprises: determining said linear or angular position based on said ratio, optionally taking into account a predefined factor K or a predefined function K of temperature.