Magnetic field sensor and Hall device

Abstract

The invention discloses a magnetic field sensor and a Hall device. The magnetic field sensor comprises a bridge circuit. The bridge circuit comprises four bridge arms. Each bridge arm comprises a Hall resistance element. At least one bridge arm also comprises an adjustable resistance element connected in series with the Hall resistance element on the corresponding bridge arm; each Hall resistance element is provided with a pair of resistance output ends and a pair of current input ends; the resistance output ends are connected to the interior of the corresponding bridge arm on which the Hall resistance element is located; and the current input ends are used for receiving working current so as to generate Hall resistance at the resistance output ends. According to the magnetic field sensor and the Hall device disclosed by the invention, the bridge circuit consists of the four Hall resistance elements and the adjustable resistance elements, and thus, bridge balance when no magnetic field exists can be realized. According to the magnetic field sensor and the Hall device disclosed by the invention, bridge differential output can be realized when a magnetic field exists, and therefore, the zero-field offset problem of the Hall device is greatly lowered structurally. The magnetic field sensor and the Hall device are simple in process and are in favor of large-scale industrialized popularization.

Description

technical field [0001] The invention relates to the measurement field, in particular to a magnetic field sensor and a Hall device that can be used in the magnetic field sensor. Background technique [0002] Semiconductor Hall resistors based on the Hall effect have the characteristics of good linearity, high sensitivity, and good stability. They have been widely used in the field of sensors to detect magnetic fields, currents, displacements, and rotational speeds. Compared with semiconductor Hall resistors, ferromagnetic alloys based on the anomalous Hall effect, such as CoPt alloys [see G.X.Miao and G.Xiao, Appl.Phys.Lett.85(2004)73], and magnetic metal multilayer films, Such as CoFe / Pt [see Chinese patent application 200610144053.6], etc., can also be used to prepare high-sensitivity Hall resistors, and has the advantages of simple preparation process and low cost. However, since the output of the anomalous Hall effect is related to the magnetism of the ferromagnetic mate...

AI Technical Summary

Problems solved by technology

Although the application achieves the balance of the bridge arm by adding an additional resistance inside the semiconductor potential well, the resistance value of the external resistance cannot be adjusted, and the ability to suppress the zero bias is limited

At the same time, the preparation process of the invention is complicated, and the formation method of the semiconductor Hall resistance cannot be applied to the Hall resistance based on the ferromagnetic film with a simpler structure and preparation process.

It can be seen that there is no better solution to the zero bias problem of the Hall device.

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