Research And Design Of Digital Temperature Sensor On Chip In Time Domain

As people's attention to health and epidemic prevention continues to increase,the demand for temperature sensors is increasing,and the product categories are becoming more diverse.The integrated temperature sensor has the characteristics of small size and low cost,and is favored by the market today.As a type of integrated temperature sensor,digital sensors have become one of the research hotspots in this field due to their low power consumption,simple structure,high integration,and high reliability.Digital sensors typically measure temperature using the temperature-dependent characteristics of a delay unit.The performance of temperature sensors with different structures is not the same.The thesis focuses on digital temperature sensors,analyzes common structures and types,discusses the effects of non-ideal factors such as process and power supply voltage on sensor performance,and introduces common correction algorithms.Due to the advantages of simple structure and small area of the temperature sensor based on ring oscillator,the design uses the ring oscillator structure as the starting point to design the temperature sensor.Based on this,the paper proposes an improved dual ring oscillator temperature sensing circuit,which uses a process resistor and a delay unit to form a temperature sensing circuit.Compared with the traditional temperature sensing circuit,the temperature sensing circuit and the temperature are improved.Linear relationship.Based on this,the thesis develops the circuit design of the digital temperature sensor,and finally uses a single point correction to further reduce the error of the digital temperature sensor.This design uses 40nm CMOS technology to complete the analog circuit and digital circuit design of the digital temperature sensor,complete the layout design of the entire circuit and verify the feasibility of the solution.In terms of customization,this design will adopt a fully customized design of analog circuits and a semi-custom design of digital circuits.The implementation will adopt a strategy of mixing the two designs and verify the feasibility of the solution.The final layout area is 0.0201mm~2,the power consumption of the circuit is 104.45μW,the accuracy is 0.203°C,and the error is 2.9°C when the measurement range is-40°C to 120°C.