Application Considerations of Multiphase Monolithic Buck Regulators with Coupled Inductors

Abstract

Power delivery requirements for computing applications have continuously grow over the years to keep up with more complex and demanding processing capabilities. The electronics industry increasingly see up to and beyond 100A power rail and microseconds transient recovery requirements for applications in wireless, healthcare, defense, industrial, and automotive industries. This thesis investigates multiphase design and application for monolithic buck switching regulators to multiply output current for low-voltage and power-intensive applications. In particular, the research incorporates coupled inductors to take advantage of its magnetic coupling between different phases to achieve minimal output ripples and ultra-fast transient response. The results of this research emphasize performance differences in control loop and transient response, output ripple, efficiency, and thermal performance when using discrete and coupled inductors at fixed output capacitance in a multiphase step-down application.