The industry is embracing gallium nitride (GaN) fieldeffect transistors (FETs) due to their superior figureof-merit (FOM). GaN is enabling engineers to design high-frequency applications running at several megahertz and improve overall power density to levels not possible before.
In this speed realm, there are considerations beyond the basic datasheet specs, which are required to appropriately select a FET driver. These hidden parameters can severely impact the design where the high operational speeds exacerbate every loss mechanism.
To enable high-frequency applications it is paramount to minimize losses, and an accurate analysis of losses is needed to identify areas of improvement. Some areas of loss are typically overlooked in slower switching applications where the conduction losses dominate total FET losses, but at higher frequencies the paradigm changes and switching-related losses dominate. Furthermore, many high speed applications use small FETs that can make switching losses in the FET driver become a larger fraction of total losses.
In this paper, I will explore these losses and show how correct FET driver choice can help mitigate them, thus allowing you to push the envelope into higher-frequency operation.