Study On Wide Temperature Compensation Method And System Design Of Silicon Piezoresistive Pressure Sensor Sensor

The development of intelligent test technology makes new requirements for the reliability and effectiveness of the signals collected.Silicon piezoresistive pressure sensor,as the most widely used device for collecting pressure information,is easily affected by temperature changes,which leads to the reduction of test accuracy.At present,the commonly used temperature compensation method can only reduce the influence of temperature drift in a small temperature range.How to realize effective temperature compensation for silicon piezoresistive pressure sensor in a wide temperature range is still a big problem up to now.To solve this problem,this paper uses COMSOL simulation software to simulate and analyze the sensor structure and temperature action mechanism.The influence of temperature on the output of piezoresistive pressure sensor is studied from the aspects of the size and structure of diaphragm,the doping concentration of the varistor,the Joule heat distribution and thermal expansion during operation,and the temperature characteristics of piezoresistive effect.On the basis of the simulation results,the mechanism of the current commonly used temperature compensation methods and their advantages and disadvantages in a wide temperature range are analyzed.Also,a new compensation scheme in a wide temperature range based on PGA309 intelligent signal conditioner is proposed,and the feasibility of realizing temperature compensation in a wide temperature range is analyzed.In order to improve the flexibility and convenience of the test,this paper proposes three design structures for the temperature compensation scheme in a wide temperature range:encapsulated type,semi-separated type and fully separated type,and studies and analyses the application conditions of the three.The structural model design,circuit layout design and mechanical package design were carried out by using Altium Designer and Solidworks related software respectively,and the physical design was completed accordingly.At the same time,a matching acquisition and control system is designed by using Lab Windows/CVI.According to the experimental platform,the results of different sensors in different compensation methods are verified and analyzed through experiments.The results show that the output zero and sensitivity of piezoresistive pressure sensors drift to different degrees before compensation,which is consistent with the previous simulation results and theories.In a wide temperature range,the compensation effect of the conventional temperature compensation method is not ideal,and the maximum temperature error after compensation only decreases from 8% to 3.4%.However,after the software algorithm compensation,the error is reduced to0.11%,which has high accuracy but poor real-time performance.After the designed temperature compensation system based on PGA309 is compensated,the maximum temperature drift error is only 0.31%,which not only ensures the real-time performance of the test,but also improves the test accuracy by an order of magnitude.The overall performance of the system is relatively good.