Correction magnetic field generating device and magnetic field sensor and correction method thereof

Abstract

The invention discloses a correction magnetic field generating device and a magnetic field sensor and a correction method thereof. The magnetic field sensor can obtain the three-axis magnetic field correction information through a built-in structure capable of generating mutually orthogonal or approximately orthogonal and uniform three-axis magnetic fields, thereby achieving the effect of self-correcting the sensing capability of a magnetic field at any time. And then, when the magnetic field sensor actually performs measurement, the measurement result can be corrected through the correction information amount, so that the accuracy of measuring the three-axis magnetic field information is improved.

Description

technical field [0001] The present invention is a magnetic field correction technology, especially a correction magnetic field generating device with a built-in correction magnetic field generation platform to generate a three-axis and uniform correction magnetic field, and a magnetic field sensor and correction device with self-correction magnetic field capabilities. method. Background technique [0002] With the advancement of technology, the application fields of smart handheld devices (such as mobile phones or wearable devices) are gradually increasing. Generally speaking, these smart handheld devices will be equipped with a magnetic field sensor for the purpose of locating position and orientation, such as: electronic compass, geomagnetic fingerprint, indoor navigation and so on. [0003] Magnetic field sensors generally utilize the magnetoresistive effect for magnetic field sensing. The so-called magnetoresistance effect (Magnetoresistance Effect, MR) refers to the e...

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Problems solved by technology

[0006] In addition, in the prior art, in order to solve the problem of inaccurate measurement of the magnetic field sensor, it is usually to adjust and change the manufacturing procedure of the magnetic field sensor to improve the measurement accuracy of the magnetic field sensor. However, this method needs to spend a lot of resources on The adjustment and improvement of the manufacturing process will lead to increased production costs or yield problems. Even if the chip manufacturer completes the chip calibration, stress changes will occur due to subsequent packaging and soldering on the circuit board and other processes (Hall effect and magnetoresistive sensors are both stress sensitive) , or the time effect makes the three-axis change different, or the temperature effect of each chip is different, and it cannot be accurately compensated, all of which cause accuracy deviation

Based on the fact that the three-axis cannot be effectively and accurately calibrated after the chip is installed, if the measurement accuracy cannot be effectively improved, the lack of accurate self-calibration capability will also cause troubles in subsequent applications.

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