2 Comments

1. 

   Mike Chen on 9th March 2021 at 5:12 am

   Is it practical to choose a 1MHz switching frequency for a Flyback converter? Maybe this frequency is too high to be implemented for today’ technology.

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     Steve on 9th March 2021 at 5:34 am

     Hello Mike, thank you for your question, high-frequency topologies are very exciting – and enabled by gallium nitride.
     In 1996, R. Watson of VPT published a paper on the active-clamp flyback (ACF) but it took until the arrival of GaN to make it feasible, when in 2017, Dr. Xiucheng Huang of VPT (now Navitas) made a 25 W ACF at 1 MHz (using GaNFast power ICs) for his PhD at VPT. This was a tiny design with planar transformer but required a TI DSP (C2000) to operate. The DSP is a great controller for high-power applications but can’t meet US DoE Level VI low-power standby requirements, so not a commercial practicality. In 2018, TI introduced the UCC28780, the first commercial ACF controller that could run up to 800kHz peak. GaNFast power ICs are rated at 2 MHz, so 1 MHz is certainly possible but we need a new controller to make it practical for industry. Thanks again for your interest. Cheers, Steve.

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