Impact of Dynamic On-Resistance of High Voltage GaN Switches on the Overall Conduction Losses

Abstract:
One of the biggest concerns using GaN-based switches is the possible increase of the dynamic on-resistance Rdyn due to the charge trapping effect when applying high voltage swings to the drain. Such dynamic behavior of the on-state resistance has a direct impact on the conduction losses. As the duration of transients with increased resistance becomes more significant under decreasing switching periods, this effect is more noticeable at higher switching frequencies. Besides the blocking-voltage, drain-current and junction temperature can also have influence on the behavior of Rdyn. To assert its impact on the conduction losses, the obtained Rdyn will be measured, mathematically modelled and compared among three GaN semiconductors.c