OFFSET ERROR COMPENSATION SYSTEMS AND METHODS IN SENSORS

摘要

Embodiments relate to reducing offset error in sensor systems. In embodiments, the sensitivity and offset of a sensor depend differently on some parameter, e.g. voltage, such that operating the sensor at two different values of the parameter can cancel the offset error. Embodiments can have applicability to stress sensors, Hall plates, vertical Hall devices, magnetoresistive sensors and others.

主权项

1. A sensor configured to sense a physical characteristic comprising:
at least one sensor element having an output, wherein an output signal comprises an offset error in an absence of the physical characteristic; an input quantity other than the physical characteristic that affects the offset error, wherein in a first phase of operation of the sensor a first input quantity produces a first output signal having a first offset error, and wherein in a second phase of operation of the sensor a second input quantity different from the first input quantity produces a second output signal having a second offset error; and offset correction circuitry coupled to the output and configured to provide a sensor output signal comprising a sum of the first output signal and a product of the second output signal and a correction factor chosen to offset a difference between the first offset error and the second offset error.