Magnetic field sensor

Abstract

The invention discloses a magnetic field sensor chip comprising a magnetic resistance sensor, a Hall sensor and a control integrated circuit, wherein the control integrated circuit is positioned in the same layer with the Hall sensor and surrounds the Hall sensor; the control integrated circuit is used for receiving and processing output signals of the magnetic resistance sensor and the Hall sensor; and the control integrated circuit comprises a power-supply biasing circuit and a signal processing circuit and further comprises a time-sequence control circuit and a signal gating circuit. The magnetic field sensor can be manufactured on a passive isolation layer. The magnetic field sensor chip of the invention can be used for detecting triaxial omnidirectional magnetic-field variation and has the advantages of low power consumption, small area, high sensitivity, strong anti-interference capacity, stable output waveform, and the like.

Description

technical field [0001] The invention generally relates to a magnetic field sensor, in particular to a monolithically integrated three-axis omnidirectional magnetic field sensor. Background technique [0002] Such as figure 1 As shown, the magnetoresistive sensor detects changes in the magnetic field parallel to the direction of the sensing element. In the anisotropic magnetoresistive bridge sensor, thin film materials with magnetoresistance effect are made on the substrate in different shapes (the substrate can be semiconductor materials such as silicon, silicon germanium, gallium arsenide or insulating materials such as silicon dioxide) ), to detect the strength and direction of the local magnetic field. Typically, magnetoresistive sensors use thin-film alloys, which are ferromagnetic alloys containing nickel and iron. The bridge structure of the magnetoresistive sensor adopts a constant voltage or current bias. When the magnitude or direction of the external magnetic fi...

AI Technical Summary

Problems solved by technology

The working principle of the Hall sensor determines that this sensor cannot detect the magnetic field parallel to the direction of the sensing element

Since the manufacturing process of the Hall sensor is consistent with the standard integrated circuit manufacturing process, US Patent US5627398 proposes a method for making a Hall sensor in a CMOS integrated circuit. This sensor can only detect the direction of the magnetic field perpendicular to the sensor.

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