Re: strange cap

On 10/07/2025 11:52 am, Sergey Kubushyn wrote:

john larkin <jl@glen--canyon.com> wrote:

https://www.mouser.com/ProductDetail/KEMET/CKC33C224KDGLCTU?qs=sGAEpiMZZMvsSlwiRhF8qtsGU%2FCnaNeQZfloC%2Fa%2FQTldKZA3leWJsw%3D%3D
>
$27 each. I think I'll use film.

 Nothing strange, just a relatively big stacked HIGH VOLTAGE and [relatively]
HIGH CAPACITANCE (at least for such voltage rating) _C0G_ ceramic capacitor.
The interesting thing is that it is sintered into a relatively small almost
monolithic block that can be installed two ways. Earlier such stacked
capacitors were made by soldering several separate caps to flat bus bar like
leads with a high temperature solder. That was adding inductance and didn't
allow the "Low Loss" mounting as it is shown in the datasheet for this one.
They also were mostly thruhole parts, with several pins on those bus bar
leads for soldering into TH pads.
 No wonder it is THAT expensive -- it is not a jellybean part that cost a
dollar per bucket and you put them all over left and right...
 A comparable film capacitor will be bigger and will have significantly
poorer ESL and ESR.

The data sheet doesn't say much about ESL and ESR - maximum values are listed on page five of the data sheet. They are clearly low, and the data sheet does spell out how the devices are structured to keep them low.
John Larkin doesn't seem to like getting his head around this kind of pesky detail.
--
Bill Sloman, Sydney