Voltage Switching Limits of Lateral GaN Power Devices

Lateral Gallium Nitride (GaN) power transistors rated up to 600 volts and vertical GaN power diodes rated up to 1,700 volts are currently available in the commercial market in low volumes [1-3]. These devices are being applied for power conversion electronics at substantially higher switching frequencies and ambient temperatures than feasible with silicon and Silicon Carbide (SiC) power devices. Important performance advantages of GaN power switching devices are low on-state resistance and inter-electrode capacitances compared to similarly rated silicon and SiC power devices. However, low capacitances also result in high switching dv/dt across the device which may cause long-term field-reliability problems. This paper reports on trade-offs in performance and reliability when using GaN power devices in power converters, especially at higher switching frequencies and ambient temperatures.