"N. Paul Taddonio" wrote: > Dear SI-List > > Can anybody comment on the effect of AC-coupling capacitors used > on a pair of matched length (200 MHZ HSTL) clocks? I have duplicated > the capacitor placement (near the driver), ie the trace lengths are all > matched, but the capacitors themselves are not matched parts. > Any guesses as to how much skew could be induced? > ~1 ps ? The difference in series impedance between a 470 pF and a 390 pF capacitor (~20% mismatch) @ 400 MHz appears to be < 0.1 ohm. > > The capacitors are 470 pF 10% X7R 0603 type. The value was chosen > for minimal impedance around 200 and 400 MHz. > > -Paul > > -------------------------------------------- > N. Paul Taddonio > > Nortel Networks, Optical Ethernet Switching > 600 Tech Park, Billerica, MA 01821, (mailstop E65-60-203) > phone: 978-288-4611 fax: 978-288-0620 > email: ptaddoni@xxxxxxxxxxxxxxxxxx > ------------------------------------------------------------------ > 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 > ------------------------------------------------------------------ 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