Biography

Enrollment Date: 2009

Graduation Date：2012

Degree：M.S.

Defense Date：2012.05.24

Department：Institute of Microelectronics，Tsinghua University

Title of Dissertation/Thesis：Research and Design of Switched-Mode Power Supply based on Digital Sliding Mode Control Algorithm

Abstract:
With the advent of mobile internet era, power management becomes more and more important. How to make portable mobile smart terminal sustainable and stability work becomes a hot research topic. Thus, power management works towards the direction of low power consumption, strong stability, high efficiency and low noise. The application of switched-mode power supply has the advantages of high efficiency, and its application in smart terminal could improve the duration time of smart terminal system. The purpose of this thesis is to design a switched-mode power supply, which has the merits of large load current, fast load transient response, small voltage ripple and high conversion efficiency, in order to meet the power requirements of multi-channel high-speed SERDES (Serializer and DeSerializer). This thesis designs a Buck converter based digital sliding mode control algorithm. In order to realize sliding mode control algorithm in digital method, a voltage controlled oscillator (VCO) circuit is used to transfer voltage signal into cyclic signal. Moreover, the use of sensor circuit transfers the monitoring and comparison of the output voltage signals into the cyclic signals. According the system state signals provided by sensor circuit, state control circuit generates control signals to control the Buck converter outside of the chip, obtaining a desired output voltage. This chip is designed with 0.18 CMOS general process. It can achieve the input voltage range of 2.2 3.3V, the regulated output voltage range of 1.2 1.8V. When the input voltage varies, the output voltage stays stability with voltage ripples of 5mV. When the input voltage is 3.3V and the output voltage is 1.2V, the maximum load current could reach 1200mA. The transient response time of load current varying is less than 5 and there is no regulated output voltage offset. The conversion efficiency is from 85% to 95% in the range of 150mA and 1200mA load current.

Publications

Papers：：

[1] Guannan Xu,Chen Jia,Hong Chen,Chun Zhang, A ultra low power dissipation CMOS bandgap reference, China Integrated Circuit, Vol.20, No.2, pp. 27 - 30, 55, 2011.

[2] Guannan Xu,Chen Jia,Chun Zhang,Zhihua Wang, A Digital Sliding Mode Controller for Switching Power Supply Converters, ASICON 2011, pp. 994 - 997, 2011.

[3] Linlin Chen,Ziqiang Wang,Chen Jia,Fule Li,Wenhan Hao,Guannan Xu,Chun Zhang,Zhihua Wang, Zero static power remote control system and the realization of transmitter, pp. 171 - 175, 2010.

Patents：

[1] Guannan Xu, Chen Jia, Ziqiang Wang, Xuqiang Zheng, Chun Zhang, Hanjun Jiang, Hong Chen, Zhihua Wang. Buck type switching power supply converter controlled by digital sliding mode variable structure: China, 201210500397.1[P]. 2014-12-10.