DESIGN AND CONTROLOF AN INTEGRATED KY DC-DC STEP-UP CONVERTER UNDER DCM OPERATION by Zeng-Wen Liang Thesis Supervisor: Dr. Chi-Seng Lam Thesis Co-Supervisors: Prof. Sai-Weng Sin and Prof. Man-Chung Wong Electrical and Computer Engineering As the development of industrial world, portable devices and wearable electronics products will be more and more popular in the coming decades. All of these products require an efficient, compact and stable power management system in order to meet modern and future society’s demand. In the power management system, DC-DC converter plays an important role and most of the converter in the market is half integrated now. Since half integrated circuit requires a large inductor or capacitor, which disobey the trend of “compact”, a fully integrated DC-DC converter will be the solution of the power management system in the future. “Boost converter” is a popular topology for step-up DC-DC converter, which has the advantages of high power efficiency and large output scale. But it has the disadvantages of large output ripple and slow transient response. After some research, another step-up converter named “KY converter” proposed in power electronics is studied and compared with “Boost converter”. Then it is discovered that the KY has smaller output ripple and fast transient response compare with Boost under the same condition. This means the “KY converter” is valuable to get further research. Then it is discovered that the KY can be applied into wearable device with “Bluetooth Smart” technology which requires less power consumption. Also NiMH battery whose rated voltage is 1.2 V can be regarded as power source in the wearable device. Finally, a fully integrated KY converter is set as target in my research work and a chip will be taped out in the coming soon.