Research And Design Of High Precision Integrated Temperature Sensor

The progress of science and technology is inseparable fromthe rapid development of integrated circuit related technology.In recent years,with the development of integratedtechnology and circuittechnology,the volume of integrated chip is shrinking and the integrated function is more and more.The integrated temperature sensor used to detect ambient temperature is one of the common components of the integrated circuit chip,which can realize the temperature detection of the circuit system online.Compared with other traditional temperature sensors,because of their high accuracy,small size and low power consumption,they have become the most widely used applications of integrated circuits.In this paper,based on the research status and actual needs at home and abroad,a high precision integrated temperature sensor including temperature sensing circuit and analog-to-digital converter circuit is researched and designed by using SMIC 0.18?m CMOS process.The temperature sensing circuit utilizes the temperature characteristics of the parasitic bipolar transistor(BJT),that is,the voltage signal VPTAT which varies linearly with temperature and the reference voltage signal VREF which is independent of temperature,and adopts the buffer circuit to obtain a relatively high driving ability,so as to meet the driving requirements of the ADC.The analog-to-digital converter is composed of a single loop,a feedforward second order E? modulator and an adaptive digital filter,which is suitable for processing near DC signal.Its function is to convert the analog temperature voltage signal generated by the temperature sensing circuit into digital signal suitable for processing.The simulation results show that in the temperature range of-40?-125?,the detection accuracy of the integrated temperature sensor circuit reaches±0.64 0?,the resolution is 0.008?,and the overall power consumption of the circuit is 4.62mW.The integrated temperature sensor circuit designed in this paper has the characteristics of high precision,lowpower consumption and wide temperature measurement range,and has a broad market prospect.