On Wed, Feb 22, 2006 at 02:20:42PM -0700, John Doty wrote: > > On Feb 22, 2006, at 11:55 AM, Bill Sloman wrote: > > >At 18:59 22-2-2006, you wrote: > >>Hello > >> > >>Does anyone has experience how much ESR a modern 2.2u ceramic > >>capacitor > >>can have? Less than 200mOhm? > > > >The manufacturers might. Google is your friend > > > >http://www.low-esr.com/esrfreqperfcurves.html-ssi#NMC2R2 > > > >For that particular capacitor, ESR is claimed to decrease with > >frequency. from about 1.5R at 1kHz to about 0.01R at 100kHz. > > When you see a spec like that, you should smell a rat. If it obeys > Ohm's law, it won't depend on frequency. If it depends on frequency, > it will almost certainly depend on other details of the test > procedure (which this site doesn't specify). The dissipation here is > probably due to dielectric hysteresis, not resistance. How that > relates to the requirements of your circuit depends on the circuit. > > Ohmic resistance of ceramics is usually very small (the electrodes > are metal), but high K ceramic dielectrics generally have a lot of > hysteresis, which can be trouble in some applications.
What does it mean? That the capacitor loses capacity when switching between charge and discharge? Like riding a snowboard with loose boots and switching edges? CL< > > John Doty Noqsi Aerospace, Ltd. > [EMAIL PROTECTED] >
