Ultra-High Frequent Switching with GaN-HEMTs using the Coss-Capacitances as non-dissipative Snubbers
Conference: PCIM Europe 2016 - International Exhibition and Conference for Power Electronics, Intelligent Motion, Renewable Energy and Energy Management
05/10/2016 - 05/12/2016 at Nürnberg, Deutschland
Proceedings: PCIM Europe 2016
Pages: 8Language: englishTyp: PDF
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Authors:
Fernandez-Serantes, Luis Alfonso; Berger, Hubert; Stocksreiter, Wolfgang; Weis, Gerald (FH JOANNEUM, University of Applied Sciences, WerkVI-Str., 8605 Kapfenberg, Austria)
Abstract:
The intent of building high efficient and very compact buck-converters with wide-band-gap transistors in a classic hard-switching operation is limited by the losses arising from dissipative reloading of the output capacitors Coss. The switching cycle of a 650V GaN-HEMT half-bridge is analyzed in terms of the Coss-related effects. A linearized model serves for deriving the relations and explaining how the Coss can be deployed for minimizing the losses. This is achieved by using Coss as an integrated non-dissipative snubber, providing soft switching for the internal transistor channel. EMI-measurements at 1MHz switching frequency are finally showing the reduction of radiated emissions when using soft-switching mode.