A magnetic sensor chip anti-electromagnetic interference structure and preparation method thereof

Abstract

The invention discloses a magnetic sensor chip anti-electromagnetic interference structure and a preparation method thereof. The magnetic sensor chip anti-electromagnetic interference structure includes multiple sets of Wheatstone double bridge structures arranged in parallel on the magnetic code disc of a magnetic encoder; each The electric angle of two Wheatstone electric bridges in the Wheatstone double electric bridge structure described in one group is 90 °, and the electric angle of the described Wheatstone double electric bridge structure of adjacent two groups is 360 °; The electric angle is defined as : When the magnetic sensor chip of the magnetic encoder is used to measure the magnetic pole signal of the code disc, the phase angle corresponding to the output voltage sine wave signal of the Wheatstone bridge in the magnetic sensor chip. Based on the magnetic pole width and the size of the magnetic code disc of the magnetic encoder, the present invention changes the common Wheatstone double bridge structure of the magnetic sensor chip into a multi-group Wheatstone double-bridge space parallel structure. The average value of the measurement results of the double bridge structure is used as the output voltage value, which can effectively reduce the fluctuation range of the output voltage signal of the magnetic sensor and improve its anti-electromagnetic interference performance.

Description

technical field [0001] The invention relates to the technical field of magnetic sensor chips, in particular to an anisotropic magnetic sensor chip anti-electromagnetic interference structure for a magnetic encoder and a preparation method thereof. Background technique [0002] The anisotropic magnetoresistance (AMR) effect is a very important physical effect in spintronics. The AMR effect was discovered by William Thomson in Fe and Ni in 1857. In 1971, Hunt first proposed to use the AMR effect of NiFe thin films to manufacture This effect has not been paid attention to and studied until after the magnetic disk head was invented. The AMR sensor chip based on NiFe film has the advantages of being sensitive to the direction of the magnetic field, high sensitivity, small size, high reliability, good temperature characteristics, high operating frequency, and strong resistance to harsh environments. Sensing, geomagnetic navigation, magnetic encoder and other fields. The core of ...

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Problems solved by technology

figure 1 It is the design schematic diagram of the Wheatstone double bridge structure magnetic sensor chip commonly used in magnetic encoders. However, when the magnetic sensor chip with this structure is working, its anti-electromagnetic interference effect is not particularly good, and it needs to be improved.

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