Multi-Mode Control with GaN High Operating Frequency Four-Switch Step-Up/Down Converter

This paper proposes a multi-mode control high-frequency four-switch step-up/down converter. By adopting the GaN switches, the operating frequency is increased, and the size of the magnetic components is reduced. PWM and PFM control strategies are introduced to improve the light load efficiency. Under PFM control, the step-up mode efficiency is improved from 35.56% to 70.11 % at 1 % load. and the step-down mode efficiency is improved from 53.53% to 67.01 % at 5% load. Under PWM control, the step-up mode efficiency is up to 91.69%. In the step-down mode, the efficiency is up to 92.93 %. Furthermore, the digital-analog hybrid control strategy enables the converter to switch between modes automatically. To verify the feasibility of the architecture and the control scheme, an experimental prototype with an input voltage of 10V, an output voltage of 5V/20V, an output power of 10W/100W, and an operating frequency of 500kHz is implemented in the laboratory.