The Chip Angle Sensing Properties Of Spin-valve Giant Magnetoresistance (gmr)

GMR material is a new kind of magnetoresistance materials. It's very valuable in sensor applications with its high sensitivity and good temperature property. Nowadays GMR material has been successfully used in some sensor applications like high resolution magnetic head used in computer, MRAM, magnetic sensors, current sensors, rotation speed sensors and so on. Spin-valve GMR is a member of GMR materials. It's not sensitive in a typical magnetic field intensity but it's very sensitive with the direction of magnetic field, and so it's useful in angular sensors. This paper studies the angular sensing properties of a typical spin-valve GMR chip with the help of some basic theories in magnetic electronics and experiment.Firstly this paper introduces some theories of GMR and applications, and also gives details of spin-valve GMR theory and the working principle of spin-valve GMR chip. The mainly work in this paper is to design a experiment in order to study the angular sensing properties of spin-valve GMR chip and discusses the experiment results based on spin-valve GMR theory and some factors in sensor design. In order to discusses the angular sensing properties of spin-valve GMR chip this paper can be divided in some different views:1,the relations of resistance of single spin-valve GMR and outside magnetic field.2,the output property of spin-valve GMR chip.3,the relations of the output and environmental temperature.4,the magnetic lag property of spin-valve GMR chip.5,the noise and outside magnetic interruptions property of spin-valve GMR chip. We got some useful results from our work.1,In a typical magnetic field intensity spin-valve GMR is not sensitive with the magnetic field intensity but it is sensitive with the direction of magnetic field, and we got some useful data; so it's very useful in angular sensors applications; and also it has some advantages when sensor is assembled since it's not sensitive with the magnetic field intensity.2,Design a structure makes the liner output higher to 160mV with a liner input about 150 in bridge of spin-valve GMR. In comparison of some typical MR angularsensors it's output make a great progress.3,The output linear resolution of the bridge is about to 0.84% and has a better property in comparison of some typical MR angular sensors.4,The output sensitivity of the bridge is about 1.0667mV/ and better than ferrimag angular sensors.5, We got the temperature property of spin-valve GMR. The results show that the temperature property data is about 0.083%/ C ,and better than semiconductors. Additionally in higher temperature it's property will be better and so it has some advantages in industries and automotive fields.6,We got the data of noise and magnetic lag in spin-valve GMR and also gives some resolutions in applications. The results show that the spin-valve GMR chip will has a better output waveform when it's filtered.