文档介绍：Integrated EMI/Thermal Design for
Switching Power Supplies
Wei Zhang
Thesis submitted to the Faculty of the
Virginia Polytechnic Institute and State University
in partial fulfillment of the requirements for the degree of
Master of Science
in
Electrical Engineering
Fred C. Lee
Dan Y. Chen
Dushan Borojevich
February 9, 1998
Blacksburg, Virginia
Keywords: EMI, Thermal, Switching power supplies
i
Integrated EMI/Thermal Design for
Switching Power Supplies
Wei Zhang
(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 ponent 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 ponents. Thermal performance of the
circuit and the temperature profile ponents 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.
ii
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 D