At all frequencies the first approximation of the network impedance is the inverse of the parallel complex admittance. Parallel ESRs by themselves are completely inadequate as a means to determine network response.. The first approximation works up to frequencies where the series interconnect impedance between the components becomes significant. At frequencies well above the SRF of the highest SRF component in the bypass network, the aggregate ESR will appear to be the parallel value, and the aggrate ESL will be the parallel value. The network impedance will be dominated at those frequencies by the parallel ESL. Knowing the ESR is helpful primarily when estimating the severity of resonance with higher frequency elements such as in-package caps, on die caps, and/or power cavities. Steve. chundi srikanth wrote: > Hi All > I need help to understand calculating the equivalent ESR of capacitors in > parallel. For example if we have tant capacitor with 65mOhm ESR and a > ceramic cap with 10mOhm ESR, whether the equivalent ESR is simply the > parallel of these two ESRs? If it is so simple then we can always keep one > ceramic and tantalums in parallel to achieve low ESR as ceramic always will > have low ESR? > > > Thank you, > Sree > > > ------------------------------------------------------------------ > 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 technical documents are available at: > http://www.si-list.net > > 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 > > > > -- Steve Weir IPBLOX, LLC 150 N. Center St. #211 Reno, NV 89501 (866) 675-4630 Business (707) 780-1951 Fax http://www.ipblox.com A Teraspeed Consulting Group LLC Partner Teraspeed Consulting Group 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax Teraspeed Labs 13610 SW Harness Lane Beaverton, OR 97008 (503) 430-1065 Business (503) 430-1285 Fax A Teraspeed Consulting Group LLC Partner http://www.teraspeed.com This e-mail contains proprietary and confidential intellectual property of IPBLOX LLC ------------------------------------------------------------------------------------------------------ Teraspeed(R) is the registered service mark of Teraspeed Consulting Group LLC ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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