On the Source of Oscillatory Behaviour during Switching of Power Enhancement Mode GaN HEMTs

Abstract

Abstract:With Gallium Nitride (GaN) device technology for power electronics applications being ramped up for volume production, an increasing amount of research is now focused on the performance of GaN power devices in circuits. In this study, an enhancement mode GaN high electron mobility transistor (HEMT) is switched in a clamped inductive switching configuration with the aim of investigating the source of oscillatory effects observed. These arise as a result of the increased switching speed capability of GaN devices compared to their silicon counterparts. The study identifies the two major mechanisms (Miller capacitance charge and parasitic common source inductance) that can lead to ringing behaviour during turn-off and considers the effect of temperature on the latter. Furthermore, the experimental results are backed by SPICE modelling to evaluate the contribution of different circuit components to oscillations. The study concludes with good design techniques that can suppress the effects discussed.

Static and Dynamic Effects of the Incomplete Ionization in Superjunction Devices

“…The rise time has been chosen taking into account the ionization time constant plotted in figure 1 in order to trigger the dynamic of the incomplete ionization. In practice, in devices such as MOSFETs, such high dV/dt are unacceptable due to other effects such as system oscillations or retriggering of on-state conduction via the Miller capacitance and gate resistance [32]. However, this value is comparable with the maximum dV/dt ruggedness reported in several datasheets of commercially available SiC devices [33,34].…”

Overview of Power Electronic Switches: A Summary of the Past, State-of-the-Art and Illumination of the Future

“…However, thanks to the benefits of wide band gap technology, some of these challenges will soon be overcome if more research goes into solving the respective problems. Recently, the field of power electronic devices has awakened to the wide band gap technology and this has resulted in the birthing of the high electron mobility transistors (HEMTs) [ 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 ]. These transistors, mostly MOSFETs and IGBTs, are made from materials such as silicon carbide (SiC), gallium nitride (GaN), indium phosphide (InP), aluminum gallium nitride (AlGaN), etc.…”

Performance Analysis of RL Damper in GaN-Based High-Frequency Boost Converter

“…This increases the risk of false turn-ON and device failures [4]. As a result, these undesired oscillations in high-frequency trend to decrease the power converter performance and reliability [5].…”