Improvement of GaN transistors working conditions to increase efficiency Of A 100W DC-DC converter

Abstract

GaN transistors can be used instead of Si MOSFET, because they improve static and dynamic performances. Moreover, low power DC-DC converters are often not very efficient, so GaN represents a good solution to improve efficiency. This article presents a comparison between Si MOSFET and GaN HEMT performances by using them in a high frequency isolated DC-DC converter. The structure and his control are described, and the maximum efficiency is higher than 94%. After having highlighted critical points for efficiency, a way to improve working conditions of GaN transistors is investigated. The converter is based on EPC GaN components.

Five-Megahertz PWM-Controlled Current-Mode Resonant DC–DC Step-Down Converter Using GaN-HEMTs

“…Other researches have validated the effectiveness of GaN-HEMTs for high switching frequency DC-DC converters [7]- [10], [14]. Also, GaN-HEMTs have been proved more effective than silicon devices in [7], [9]- [11], [13]. However, because of GaN-HEMTs having low gate-tosource threshold voltage V th , low maximum gate-to-source voltage V GSS , and high source-to-drain voltage V SD , it is difficult to drive GaN-HEMTs.…”

Design of a compact, ultra high efficient isolated DC-DC converter utilizing GaN devices

“…In paper [14], isolated dc-dc buck converter for 48V input to 12V output with a switching frequency of 1.6MHz at an output power of 360W is presented to obtain a maximum efficiency of around 97%. References [15][16][17] are about isolated dc-dc converter applications in low input voltage applications and switching at a very high frequency of MHz to obtain the efficiency of around 95%.…”

5MHz PWM-controlled current-mode resonant DC-DC converter using GaN-FETs

“…From these reasons, GaN-FET can realize low P d . Also, another researches have been proved utilizing GaN-FET for high switching frequency DC-DC converter is very practical [8][9][10]. Some literatures [11][12][13] prove that GaN devices are more effective than silicon devices.…”