Sensor for identifying magnetism of medium

Abstract

The invention discloses a sensor for identifying magnetism of a medium. The sensor comprises a chip (21), a printed circuit board (22) and an output pin (23), an input end and an output end of the chip (21) are respectively welded with corresponding wiring ends on the printed circuit board (22), and one end of the output pin (23) is welded with a corresponding wiring end of the printed circuit board (22), so that the output pin (23) is conducted with the input end and the output end of the chip (21). The sensor is applicable to identifying the magnetism of the medium made of hard magnetic materials. The sensor is provided with an MTJ (magnetic tunnel junction) element, the MTJ element is high in sensitivity and signal-to-noise ratio as compared with an indium antimonide Hall element, and accordingly the sensor is high in sensitivity and signal-to-noise ratio. In addition, the MTJ element is suitable for mass production, is simple and mature in manufacturing process, is not affected by temperature or strain easily and is high in yield, so that the sensor is simple in processing technology and low in cost. Besides, the sensor does not need a permanent magnet and is simple in structure and low in cost.

Description

technical field [0001] The invention relates to the technical field of magnetic sensors, in particular to a magnetic sensor for identifying media such as banknotes and magnetic cards. Background technique [0002] In daily life, media such as banknotes and magnetic cards are widely used. Generally, the magnetic properties of media such as banknotes and magnetic cards are very weak, therefore, sensors for identifying the magnetic properties of media such as magnetic heads of currency detectors need to have high sensitivity, low noise and high signal-to-noise ratio. [0003] In the prior art, a sensor for identifying the magnetic properties of a medium usually uses an indium antimonide (InSb) Hall element. This sensor has the following disadvantages: [0004] (1) The sensitivity and signal-to-noise ratio of indium antimonide Hall elements are very low, resulting in very low sensitivity and signal-to-noise ratio of this sensor; [0005] (2) The manufacturing process of the i...

AI Technical Summary

Problems solved by technology

[0004] (1) The sensitivity and signal-to-noise ratio of indium antimonide Hall elements are very low, resulting in very low sensitivity and signal-to-noise ratio of this sensor;

[0005] (2) The manufacturing process of the indium antimonide Hall element is complicated, and it is ob

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