Hi,
Polypropylene capacitors are no longer the only choice in the ~20nF/1kV+ range. Now there are C0G MLCCs as well. It makes me think whether they would work reliably as the LLC resonant capcitors, in split capacitor resonant half-bridge topology preferably. The polypropylene high frequency derating curves are available, but I see no similar specification for the ceramics. So is there any derating needed, besides the obvious dissipation factor/ESR limited heating?
Best regards, Piotr