PELS 2000 Prize Paper Awards

Design of Microfabricated Inductors

Luca Daniel
University of California, Berkeley, CA

Charles Sullivan
was with University of California, Berkeley, CA when this work was performed. Is now with Dartmouth College, Hanover, NH

Seth Sanders
University of California, Berkeley, CA

Abstract - Possible configurations for microfabricated inductors are considered. Inductance can be set by adjusting perme-ability through control of anisotropy of a permalloy core or via a patterned quasi-distributed gap. A design methodology based on a simple model is proposed. A more accurate model and a numerical optimization are also developed. Design examples for 5- and 10-MHz buck converters and 2.5-MHz resonant converter applications are presented.

Simple Analytical and Graphical Methods for Carrier-Based PWM-VSI Drives

Ahmet Hava
Yaskawa Electric America, Inc., Waukegan, IL

Russel Kerkman
Rockwell Automation/Allen Bradley, Mequon, WI

Thomas Lipo
University of Wisconsin, Madison, WI

Abstract -This paper provides analytical and graphical methods for the study, performance evaluation, and design of the modern carrier-based pulsewidth modulators (PWM's), which are widely employed in PWM voltage-source inverter (VSI) drives. Simple techniques for generating the modulation waves of the high-performance PWM methods are described. The two most important modulator characteristics&emdash;the current ripple and the switching losses&emdash;are analytically modeled. The graphical illustration of these often complex multivariable functions accelerate the learning process and help one understand the microscopic (per-carrier cycle) and macroscopic (per fundamental cycle) behavior of all the modern PWM methods. The analytical formulas and graphics are valuable educational tools. They also aid the design and implementation of the high-performance PWM methods.

Design of Smart Power Synchronous Rectifier

Honglin Pan
National University of Singapore, Singapore

Yung C. Liang
National University of Singapore, Singapore

Ramesh Oruganti
National University of Singapore, Singapore

Abstract -In low-output-voltage dc/dc converters, power losses due to the conduction of rectifying devices are significant. Using synchronous rectifiers instead of the conventional fast recovery diodes or Schottky diodes is an effective solution to this problem in most topologies. However, for synchronous rectifiers to perform effectively, it requires an external gate drive with proper sensing and timing control circuits. This can increase the complexity and cost in converter hardware implementation. For the first time, a smart power synchronous rectifier (SPSR), which is a two-terminal MOS rectifier, is designed to overcome this difficulty. The SPSR integrates a simple control unit with a power MOSFET into a smart module to form a self-controlled synchronous rectifier. It has great advantages over the conventional discrete circuit composition, such as integrated gate control, precise timing switching, and fast transient response, which are suitable for applications in high-frequency pulsewidth modulation (PWM) converter circuits.