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MLCC Capacitors and my experiments of DC bias on Capacitance
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SteveyG:
I took a little look at how Class II Ceramic Capacitors change in capacitance with applied DC which some of you may find useful.

The video describes more, but essentially the capacitance decreases with increased electric field in the dielectric material. At the maximum working voltage of the capacitor, the capacitance may only be 20% of the originally specified value so something to watch out for in your design if you are not already aware of this effect.

C0G, NP0 (Class I) capacitors are not effected in the same way by DC bias.

I hope this helps someone


laneboysrc:
Thanks for this informative video!

While I have seen already a few  other videos discussing this topic, yours is certainly standing out because it is very well explained and demonstrated. :-+

Thanks for also measuring other capacitor types and showing their different characteristics 

cheers, Werner
Siwastaja:
Thanks for spreading the word.

Most know the phenomenon as of now, but the details do matter, and #1 giveaway is: never assume any characteristic based on dielectric name; look for the actual curves. If the curves don't exist, and if the capacitance is of any importance, do your own measurements. For example, widely touted assumptions that X7R only go down to 40-50% with full rated DC voltage, and only Y5V are worse than that, are wrong. Some X7R parts are as poor as some Y5V parts.
The Electrician:
TDK has a couple of videos on this topic:



xavier60:
They can also lose capacitance with age,
https://www.johansondielectrics.com/ceramic-capacitor-aging-made-simple
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