Design Of CMOS Analog Temperature Sensor

In this thesis, the developing history, present situation and trends of temperature sensor and CMOS integrated temperature sensor were summarized. The dominance and properties of the CMOS integrated temperature sensor were also described, the research meaning was pointed out. The temperature related model and the influencing factor of two temperature sensing devices, PNP substrate transistor, based on CMOS process were analyzed and compared, and pointed out that the PNP substrate transistor was more fit for being the temperature sensing device.This thesis focuses on the study and design of an integrated temperature sensor based on the standard CMOS process. This Temperature sensor can be used for the accurate measurement of the temperature or the ambient temperature, and it has the advantages of small size, wide measuring range and high precision. The major design of this thesis includes the research of the types of temperature sensor and the different measurement methods, the research of theΣ-Δconversion technology, the research and design of the whole system structure of the temperature sensor and every function module of the temperature converter, and the research and design of the digital filter. In this thesis, the temperature sensor can be divided into two parts: integrated temperature converter and digital filter. The integrated temperature converter is composed by temperature component, acquisition circuits of the complementary to absolute temperature and the proportional to absolute temperature, 1.2V and 0.6V high precision bandgap voltage source, voltage comparator, CMOS switch circuit, and etc.This temperature sensor is designed and simulated by Virtuoso and Spectre which are products of Cadence. All the device models are offered by 0.18um CMOS process module of SMIC. The working voltage of the temperature converter is 3V, maximum power consumption is less than 3mW, and it can measure the temperature ranging from-20℃to 60℃, and the minimum accuracy is 0.2℃.