Magnetic Resistance Sensor Signal Processing Circuit Testing And Optimization Design

Human beings perceive changes in the outside world by means of their five senses.In the Internet of things,sensors are the five senses of human beings.Therefore,sensors play an indispensable role in the field of Internet of things.In recent years,with the rapid development of the Internet of things,sensors are also used in various fields.Magnetoresistive sensors convert changes in the magnetic field into electrical signals.Therefore,magnetoresistive sensors are widely used in many fields.For example,aerospace,medical,Marine and other fields.With the development of integrated circuits,the size of circuits is getting smaller and smaller,which provides convenience for the application of sensors.Therefore,it is very important to design a signal processing integrated circuit for magnetic resistance sensor.This subject adopts TMR magnetic resistance sensor,due to its output signal is weak,so the signal processing circuit of the influence factors may cause interference to the signal.For this reason,the existing instrument amplifier in the laboratory is tested.The test results show that it has poor inhibition ability to high-frequency ripple,and its output amplitude of high-frequency ripple is 13 mV.Therefore,the design of the instrument amplifier is optimized,and the simulation results show that the ripple amplitude can be reduced to 19.6 V.In addition,the common mode rejection ratio is optimized,and the imitation result can reach 174.7dB after common mode rejection ratio.Its equivalent input noise and closed-loop gain also meet the design requirements,and its values are 15.25nV/ sqrt(Hz)and 40 dB.According to the demand of power supply,bandgap reference voltage source should have low temperature drift coefficient and high PSRR.This topic bandgap voltage reference source adopts the piecewise compensation structure,to achieve low temperature coefficient.The PSRR improvement module is also used to achieve high PSRR.The simulation results showed that the temperature drift coefficient was 1.929 ppm/? and PSRR was 104.2dB.