Paralleling Devices in a 13.56 MHz Class Φ₂Inverter to Achieve Current Splitting and Improve Device Thermal Performance

This paper presents a comparison between the operation of a 13.56 MHz Class Φ2 inverter using one or multiple gallium nitride (GaN) switching devices in parallel. In high-frequency, high-power applications such as plasma generation, the GaN device is advantageous due to its low switching losses and on-resistance, evident in simulations. However, as the frequency and power increase, the power dissipation in the devices increases. Using device parallelization for current splitting, we can reduce the losses, which leads to lower device heating, thereby reducing device stress and enhancing the overall thermal management. This paper shows that current splitting effectively reduces the temperature rise across an individual switching device. Using the optimal number of paralleled devices, the steady-state case temperature of each device is almost halved in a multi-device inverter compared to a single-device inverter.