[R-390] CAPACITOR FIGHT

[David Wise]

I tried to calculate the reliability of film/foil vs. ceramic for C553 and got unclear results; it depended on the method I used.  Both types had a definite voltage derating effect; if you pick something rated at 1kV or more, it's overwhelmingly likely that your cap will outlast many generations, which realistically speaking is so far in the future it's meaningless.

Do burn in your part before installing it, by floating it at its rated voltage and temperature for a few days.  If it gets past that, you're not likely to see an infant-mortality event.

I also simulated a metalized-film self-heal event in SPICE, and got an 80mA current peak that lasted 10us.  I don't think this will heat the wire enough to fuse it, but who wants to test it when film/foils are still readily available?

Dave Wise