Hi Bill, The reason is that there is almost no inductance with planer caps, besides the discrete may have large. As you know, discrete caps behave inductor rather than capacitor @ high frequency, so that impedance curve is shown as "V" shape. You can only get effect at the bottom of "V". Regards, On Fri, 9 Aug 2002 10:38:57 -0700 "Bill Mueller" <williamm@xxxxxxx> wrote: > Hello All, > > I've been doing digital design guides for a little over a year now, > and was interested in a little more explanation on why planer > capacitors are more effective at higher frequencies than discrete > caps. > > Also, if you have a fairly large stack up (10+ layers) with several > possible planer caps are there any additional considerations to be > made? > > Thanks, > Bill > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > //// /// // / / / / / / / / / / Tadashi Arai//Platform Developing Dept.,Desktop Prd Div. Fujitsu Limited arap@xxxxxxxxxxxxxx TEL:+81-42-370-7624 Inagi-shi, Tokyo, Japan / / / / / / / / / / / // /// ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu