| Summary: | 碩士 === 國立雲林科技大學 === 電子工程系 === 106 === In recent years, advances in integrated circuit manufacturing processes have led to the continuous shrinkage of transistors, which has increased the density of MOS transistor per unit area, and the operating speed has continuously increased. As a result, the power density of the system chip has become higher and higher, and the operating temperature of the chip has increased. In general, an integrated circuit chip easily causes malfunction or crash in a high-temperature environment. In addition to effective heat dissipation, more and more embedded temperature sensing circuits are used in the system chip to sense the temperature and monitor the temperature in real time, and the overheat protection circuit is used to achieve the normal operation of the chip. Therefore, this thesis focuses on the issue of chip temperature sensing and studies the embedded sensing circuit. Embedded temperature sensors are analyzed from the literature the imbedded temperature sensors classified as analog and digital types depending on the circuit style. The analog temperature sensor, although it has a good temperature sensing response and excellent resolution, the analog circuit is not easy to migrate in a different process, and the analog temperature sensing circuit integrated into the digital system will also have some difficulties. Therefore, this thesis also studies the simpler all-digital temperature sensor applied to the digital system. The literature on digital temperature sensors can be divided into delay type and ring type temperature sensors. From the literature study, it is known that ring oscillators are simple and small in the area when used as temperature sensor components, and are suitable for digital embedded system chip designs. However, ring-oscillating temperature sensors are very susceptible to fluctuations in the supply voltage and increase the error in temperature sensing.
The ring-oscillating temperature sensor is susceptible to the supply voltage. This thesis proposes an all-digit differential delay cell circuit with supply voltage variation and negative feedback compensation to instantly compensate for the slight change in voltage. The proposed ring-oscillating temperature sensor only reacts to the output oscillation frequency when the temperature changes. In this thesis, when the delayed cell element connected to a ring oscillator, the temperature can sense temperature changes by quantifying the oscillation frequency. This circuit simulated in a 0.18μm CMOS process. The temperature range is 0°C~100°C, and the temperature resolution is 0.1°C. The supply voltage is 1.8V±10%, and the voltage variation sensitivity is as low as 0.016MHz. /mV, compared to the traditional differential ring oscillator, the voltage sensitivity can be improved by up to 90%.
|
|---|
