Switching Performance Comparison of Low-Voltage GaN and Si Devices

This paper presents a comprehensive comparison of the switching performance of low-voltage (100 V) Gallium Nitride (GaN) transistors and Silicon (Si) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), featuring some of the lowest R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(on)</inf> devices on the market. Key performance parameters, including turn-on and turn-off switching losses, gate driver losses, and lumped R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(on)</inf>, are evaluated using an indirect noninvasive method. Results show that GaN devices achieve at least 42% lower turn-off losses, 45% lower turn-on losses, and 71% lower gate driver losses compared to Si counterparts. However, GaN devices are highly sensitive to dead-time (DT) control, requiring precise tuning to fully exploit their low turn-off losses. Additionally, GaN devices exhibit a lumped dynamic R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS(on)</inf> 3–4 times higher than static values at 1 MHz, posing concerns for high-conduction-loss applications. These findings underscore the trade-offs between GaN and Si devices in optimizing low-voltage converter designs.