Giant magneto-resistance sensor differential drive and magnetic field bias circuit and bias method

Abstract

The invention discloses a giant magneto-resistance sensor differential drive and magnetic field bias circuit and a bias method. The circuit comprises two operational amplifiers; input power passes through a power reference module and is then inputted to one negative electrode and one positive electrode of the two operational amplifiers respectively to enable the two operational amplifiers to generate stable and amplified positive and negative voltage, and the two operational amplifiers are connected with the positive power end and the negative power end of the giant magneto-resistance sensor respectively to serve as drive voltage of a giant magneto-resistance chip; and output of one operational amplifier passes through a diode, an adjustable resistor and a decoupling capacitor at the same time to be connected to one end of a coil, and the other end of the coil is grounded. Through adjusting the adjustable resistor, current passing through the coil is changed, and a changeable bias magnetic field is thus generated.

Description

technical field [0001] The present invention relates to a sensor drive method and circuit, in particular to a giant magnetoresistance sensor differential drive and magnetic field bias circuit and bias method, the giant magnetoresistance sensor differential drive and magnetic field bias circuit and bias method is a sensor It provides a stable differential power supply and provides additional amplification for the output of the sensor; the external bias magnetic field can adjust the operating point of the sensor, so that the sensor can output bipolar signals. It belongs to the field of sensor technology. [0002] Background technique: [0003] Due to its small size, high sensitivity, easy installation, and high three-axis vertical accuracy, the giant magnetoresistance effect magnetic field sensor is used for detection. In the field of magnetic field detection with space restrictions and pointing requirements, the giant magnetoresistance effect magnetic field sensor is a very ...

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Problems solved by technology

[0008]So although these above-mentioned patents all relate to the sensor of giant magnetoresistance and its application, and all do to giant magnetoresistance sensor or the method that utilizes giant magnetoresistance sensor to detect However, there are no suggestions on how to improve the giant magnetoresistance sensor to maintain accurate detection performance in a strong magnetic field environment. Therefore, under a strong magnetic field, the giant magnetoresistance sensor is often magnetized by an external magnetic field. However, the problem of affecting the detection accuracy still exists. At the same time, the signal detected by the sensor will be affected by environmental parameters such as external temperature, and the signal transmitted by the magnetic sensor is prone to distortion, which still needs to be further improved.

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