Integrated EMI/Thermal Design for Switching Power Supplies

(ABSTRACT) This work presents the modeling and analysis of EMI and thermal performance for switch power supply by using the CAD tools. The methodology and design guidelines are developed. By using a boost PFC circuit as an example, an equivalent circuit model is built for EMI noise prediction and analysis. The parasitic elements of circuit layout and components are extracted analytically or by using CAD tools. Based on the model, circuit layout and magnetic component design are modified to minimize circuit EMI. EMI filter can be designed at an early stage without prototype implementation. In the second part, thermal analyses are conducted for the circuit by using the software Flotherm, which includes the mechanism of conduction, convection and radiation. Thermal models are built for the components. Thermal performance of the circuit and the temperature profile of components are predicted. Improved thermal management and winding arrangement are investigated to reduce temperature. In the third part, several circuit layouts and inductor design examples are checked from both the EMI and thermal point of view. Insightful information is obtained. Acknowledgements iii Acknowledgements I would like to express the deepest and sincere gratitude for my advisors Dr. Fred C. Lee and Dr. Dan Y. Chen, for their guidance and great support during the work. The extensive knowledge and insightful advice of Dr. Lee have guided me thorough the research. The many helpful suggestions and detail discussions with Dr. Chen enable me to finish the work. Without the help from them, it is impossible for me to start and finish the work. I must also thank my Master's committee member Dr. Dushan Borojevich, for his great support regarding the research. for their initiative guidance and help in the study. I would like to express my appreciation to Mr. for their friendship and sharing the knowledge with me. Finally I would like to dedicate the thesis to my dear parents, Guowei Zhang and Sufang Ren, for their love and support in these years. The great thank goes to my mother for her accompanying me and sacrifice during the time for preparing the thesis.