Research And Design On Time-domain Digital Temperature Sensors And Integration

With the continuous development of the process,the transistor size is getting smaller and smaller,and the integration on a single chip is getting higher and higher.On one hand,it improves the performance of the circuit greatly.On the other hand,it makes the circuit more sensitive to environmental variables such as temperature and voltage.These variables make the behavior of the circuit unpredictable,leading to serious reliability problems.The temperature variable is an important cause of abnormal aging and failure of the circuit.Detecting and controlling the various environmental variables on chips is one of the most effective ways to improve reliability,so more and more designers are now paying attention to sensors which used to detect the working environment of circuits.However,it is not easy to integrate the sensors on the chip,because the number and the placement of sensors are limited by power consumption,area,and compatibility.Digital component-based sensors are a viable technology for solving these problems.This paper mainly studies the design of digital temperature sensors in the time domain,which use the advantages of digital circuits effectively in terms of integration,power consumption,and area overhead.This paper introduces the design and implementation of two time-domain temperature sensors and gives the detailed simulation results.This type of sensors is mainly composed of digital components and has a relatively simple design principle.The general time-domain temperature sensors are mainly composed of three parts,which are the sensing part,the time-to-digital converter part and the calibration module.The performance of these circuits can be optimized by adjusting the structures of the sensing part and the parameters of the conversion section.The accuracy,error,and measurement range can be trade off according to the specific applications.This paper introduces a time-domain temperature sensor which is based on a single ring-oscillator.And then another time-domain dual-ring based temperature sensor is designed and implemented whose performances on voltage variable sensitivity and dependency on reference signal are improved greatly.