Research And Design Of Digital Temperature Sensor Based On 22nm Finfet Process

Digital Temperature Sensor(DTS),as a circuit that converts temperature into a readable binary code in real time,prevents irreversible damage to the chip at high temperatures and plays a vital role in temperature monitoring.In recent years,with the rapid development of large-scale integrated circuits and the increasingly advanced manufacturing processes,the high-precision characteristics of temperature sensors have made them widely used in commercial production.However,in mobile chip applications,the existing temperature sensor can only meet the high precision requirements,and can not detect the rapid change of 50?s/°C in the internal temperature of the So C.Therefore,obtaining the accurate temperature value in real time is a key problem to be solved by the temperature sensor.It is necessary to realize the DTS circuit structure that weighs the real-time and accuracy.In this thesis,for high-precision and real-time application requirements,based on the 22 nm Fin FET process,the circuit and layout design are realized by analyzing the DTS bandgap reference and the circuit structure of the ADC.First of all,design the bandgap and sigma-delta ADC of DTS,and then finish the function of top circuit.In order to achieve high-precision performance of DTS,the bandgap reference structure with high-order compensation of resistance is first selected,and the resistance adjustment circuit covering the range of voltage value is realized at the same time.Secondly,the first-order sigma-delta ADC structure with improved output resistance of the comparator is selected.Finally,the offset and slope values are introduced to calibrate the formula.At the same time,in order to balance the speed characteristics,the parallel analog circuit structure and self-calibration mode are used to reduce the counter time,and the variety of clock division mode to control sleep time is increased to reduce power consumption.Based on the 22 nm Fin FET process,this thesis designs a 10-bit binary coded DTS to achieve the high speed and real-time performance.In the aspects of the system structure,high-order resistance compensation,improved output resistance,two-phase non-overlapping clock,self-calibration circuit,formula calibration and sleep mode,the DTS circuit designed is simulated,the layout is realized and the test results are verified.Based on the default 40 MHz clock condition,the DTS circuit designed in this thesis achieves the target of the conversion time within 20?s,the temperature resolution of 1?and the error rate of ±3?.By analyzing the verification results of high-precision characteristics,the DTS circuit can control the temperature coefficient below 27 ppm under the high-order compensation of the bandgap reference;then the output voltage can be stabilized at 0.9V by adjusting the resistance circuit covering ±300m V range;the gain of the comparator can be increased to 105 d B;finally,the offset and slope calibration formula is used to obtain the temperature output code with the error within ±3?.According to the verification result of the real-time characteristics,DTS reduces the calibration time to 16.5?s by the parallel circuit and the self-calibration mode.In summary,the DTS circuit designed in this thesis can take good care of both high-precision and real-time characteristics.Based on the 1.8V analog voltage and 0.9V digital voltage supply,the BJT and temperature sensor of layout areas are 23.22?m × 48.20?m and 99.54?m × 159.84?m,respectively.