The equation is BW = 0.35/risetime. See Howard Johnson and Martin Graham's "High Speed Digital Design, A Handbook of Black Magic" Appendix B for details. Tom Dagostino Teraspeed Consulting Group LLC Device Modeling Division 13610 SW Harness Lane Beaverton, OR 97008 503-430-1065 tom@xxxxxxxxxxxxx <mailto:tom@xxxxxxxxxxxxx> Teraspeed Consulting Group LLC 2926 SE Yamhill St. Portland, OR 97214 http://www.teraspeed.com <http://www.teraspeed.com> Teraspeed (SM) is the service mark of Teraspeed Consulting Group LLC -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Kong Chuan Susanto Sent: Thursday, April 29, 2004 9:58 AM To: meng.yubao@xxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: uper to How high the frequency to scan is sufficient for target impedance of Power distribution system Hi Meng, I have read some papers that use 'risetime/0.35' for the upper bound frequency. However I'm not sure where this thing comes from. Perhaps others can comment on this too. The lower bound basically is from DC. Regards, Chuan > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx > [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of > meng.yubao@xxxxxxxxxx > Sent: Monday, April 26, 2004 2:52 AM > To: si-list@xxxxxxxxxxxxx; si-list-bounce@xxxxxxxxxxxxx > Subject: [SI-LIST] uper to How high the frequency to scan is > sufficient for target impedance of Power distribution system > > > HI: > For a highspeed digital system PCB, we should control its > PDS Impedance > not to exceed its target Impedance from low frequency uper to high > frequency, but how higher the upper frequency is good enough, and how > lower the frequency ? Deducing from the Pulse width of the PCB > simultaneous switch noise or from the signal rise/fall edge > and its pulse > width ? Can anyone give me some clear equation! > regards > meng yubao > > ------------------------------------------------------------------ > 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: > http://www.freelists.org/webpage/si-list > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > http://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 > > > ------------------------------------------------------------------ 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: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: http://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 ------------------------------------------------------------------ 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: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: http://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