Extensive technical literature suggests that GaN is the ideal power device for high-frequency power conversion. The lecture provides an in-depth analysis of the key features that make GaN technology attractive and highly efficient at high switching frequencies, up to the ~1MHz range. The presentation is structured in two main sections. The first one includes a quick overview and positioning of the three different semiconductor technologies (Si, SiC, GaN). The key physical characteristics of each of them are very briefly explained, with the purpose to provide a positioning of them in different applications. This will also allow to introduce the expected benefits of GaN at high switching frequency operation. The second section, which is the core of the lecture, is focused on examples of topologies suitable for soft switching operation at high switching frequency, selected inside popular Switch Mode Power Supply (SMPS) applications. For each of these topologies, we start with a general quick description of the operation principle, then we explain the value proposition of GaN there, by highlighting the GaN electrical parameters enabling high performance at high switching frequency. When applicable, we show the expected benefits of both High-Voltage and Medium-Voltage GaN devices. The description is also complemented with some practical application examples. Especially through these application examples, recommendations and general guidelines are provided in order to optimize the soft switching operation of GaN devices at high switching frequency. Analyzed power converter topologies 1. LLC Converter 2. Triangular Current Mode (TCM) PFC 3. Cyclo-converter 4. Hybrid Flyback 5. Dual Active Bridge (DAB)
