Offset error compensation systems and methods in sensors

Abstract

The embodiments of the invention relates to offset error compensation systems and methods in sensors. 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.

Description

technical field [0001] The present invention relates generally to sensors, and more particularly to compensation for offset errors in sensors. Background technique [0002] Sensors are often used as sensor bridges, for example with four identical sensor elements coupled in a Wheatstone bridge configuration. The bridge circuit is supplied with voltage or current and provides different output voltages. Examples of this include strain sensors, magnetoresistive sensors, Hall plates, and vertical Hall devices, among others. [0003] However, a common problem with sensor bridges is offset error. Offset is the output signal when there is no physical quantity that the sensor should detect. For example. For a Hall plate, the offset is the output signal at zero applied magnetic field, and for a stress sensor, the offset is the output signal at zero mechanical stress. Typically, the source of offset error is a small mismatch between the sensor elements of the bridge. In other wor...

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Problems solved by technology

However, this method still produces a small offset error, which is called residual offset

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