DF & ESR

For a ceramic, 40 ohms seems way high -- 0.1 ohms seems far more believable. 40 ohms would be more reasonable in a large cheap 'lytic.

Why are you going from the dissipation factor if you have the impedance vs. frequency?

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Actually, as I recall, that is correct. I remember Z vs. F plots showing Re(Z) going way up at LF, corresponding to a constant DF.

What matters is how you use it. If you want realistic figures, measure it under the conditions you'll be using it under. If you are using it at 1kHz, an ESR of 40 ohms isn't going to matter much, since Xc is rather large at

1.59kohms! If you're actually using it for high-frequency bypass, then you aren't really using it at 1kHz anymore, you want to look at the harmonics that go up into the MHz.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms