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
We used 2 630V caps in a split arrangement, single half bridge driver LLC 230V converter - and had good margin
AFAIR it was a TDK C0G
I can look specific part number up tomorrow
Cheers
Klaus
Only current AFAIK.
You sometimes see current ratings in the datasheet, but if not, a good guess would be to limit power dissipation to half that of a resistor in the same package. So, 1206, 62mW, etc. Then use ESR from the Z(F) curve to get current.
Even with induction heating experiments, I can't recall actually making them heat up. They handle a lot of VAs.
I put a 47nF C0G in a recent LLC resonant project (mind, only 10W), doesn't get perceptibly warm by itself (it's all the other stuff around it that's getting hot).
Tim
-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website:
We used this one:
CGA5C4C0G2J151J060AA
Rats, no current rating:
Tim
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