Available at: https://digitalcommons.calpoly.edu/theses/3435
Date of Award
12-2026
Degree Name
MS in Electrical Engineering
Department/Program
Electrical Engineering
College
College of Engineering
Advisor
Taufik
Advisor Department
Electrical Engineering
Advisor College
College of Engineering
Abstract
This work presents the novel design of a DC-DC four phase modified interleaved buck converter topology and its accompanying control scheme. The design is optimized for high step-down DC-DC voltage conversion, high output current, and is controlled via the duty-cycle of the switching components, achieving a transfer function of D/4. The converter uses voltage balancing to distribute the input voltage across flying capacitors, reducing stresses across switching components, reducing component values, and permitting the increase of the duty cycle for a given output voltage. This work addresses the by-component current and voltage waveform derivations throughout the five operating phases, and validates those performances in LTspice simulation software. A by-component loss breakdown and efficiency estimation is computed, as well as a simulated efficiency comparison to a standard multiphase buck converter. The proposed converter outperforms the multiphase buck across its 80A output load current. When asynchronously implemented in a 48-1V application, the full-load efficiency is 63.46% at 60A. When synchronously implemented for the same application, the full load efficiency reaches 91.33%. While intended to address the high step-down ratio from a 48V DC bus in a data center to supply the necessary 1V to XPU ASIC devices, the converter may be used for any number of high step-down applications. It offers advantageous di/dt characteristics over comparable switch controlled converters, reduced electromagnetic interference (EMI), reduced component values, accurate voltage regulation, and advantageous thermal qualities.