Design And Research Of Temperature Adaptive System For Spin-valve Sensor

In the era of Internet of things,magnetic sensor is an important branch of the sensor industry,and its application has a huge market.Among this,giant magneto-resistance(GMR)sensor is widely used in automotive electronic systems,industrial control systems,medical devices and other technical fields,because of its advantages of high sensitivity,low energy consumption,small size and so on.The GMR sensor always work in harsh environment,the component parameters are affected by temperature,which leads to the output deviation of the GMR sensor and cause the temperature drift phenomenon.Therefore,in the high precision detection applications,temperature compensation is necessary.Based on the above realities,this thesis mainly studies on the working principle and temperature characteristics of the spin-valve sensor.Then propose a temperature-adaptive scheme based on programmable gain amplifier(PGA).This scheme adopts the method of combination of software and hardware.It deals with the dynamic relationship between temperature and the gain of PGA through the algorithm of look-up table,and uses microprocessor control PGA to realize temperature-adaptive function.Specific work is as follows:(1)Analyze the associated background and practical significance of this research.Focus on investigating the development of application of magneto-resistance sensors based on spin-valve and temperature compensation technology of sensors.(2)Study and implement the overall software and hardware design of this system.Each module circuit principle of the temperature compensation system is introduced in detail,and the temperature-adaptive function is realized with the data processing algorithm,which solves the problem of the temperature interval division and the frequent jump in temperature overlapping area.(3)Analyze a large number of data,which collected by high-low temperature magnetic sensor testing system.And obtains a significant result,the maximum drifting error of sensitivity is reduced by roughly an order of magnitude.It shows that the system is reliable.