The Design And Application Of High Performance CMOS Comparator

With the rapid development of electronic information industry and the increasing demand of power saving, the modern society entered to a brand-new information age. As is known to all, the most important part of the microelectronic technique, which is the foundation of information technology, is the analog IC. It is widely used in various ways, such as:sampling, amplify, compare, transmission, power supply, etc. It is the bridge between the real world and the digital system. In this way, the analog IC's performance will restrict the whole system's performance. The high precision sub-circuit becomes the trend of analog IC design.This thesis puts forward the design motheds of low power and high accuracy sub-circuits which based on the PWM DC-DC system. The main work and achievements are listed as follows:Firstly, this dissertation focuses on the control IC of PWM DC-DC. By using Charter 0.35μm CMOS and SMIC 0.18μm CMOS process, a high precision and low power core control module PWM comparator are designed and post-simulation verified.Secondly, based on the designed dynamic comparator and SMIC 0.18μm CMOS process, a high precision sampling circuit is designed and post-simulation verified. Then the MATLAB software is adopted to process the simulation data and obtain the dynamic characteristics, the spurious-free dynamic range (SFDR) is used as a main evaluation standard.At last, based on the design of the dynamic comparator and the high precision sampling circuit, the whole system simulation of the PWM DC-DC is performed by using SPECTRE. The simulation results show that this design can perfectly replace the traditional PWM comparator, with the advantage of higher precision and lower power. At last, the dynamic comparator is modified in order to improve the frequency response. This dissertation provides a perfect circuit structure for low power and high performance system.