Daniel, I try to put a bulk capacitor on each power-supply voltage close to: * Where it enters a card (or at the output of a linear regulator or DC-DC converter that generates the voltage). * Where it leaves the card, through a cable to a peripheral device or a socket for a SIMM/DIMM or daughter/adapter card. * Power hogs, such as microprocessors, memory modules, clock generators, DC-DC converters, and linear regulators. AND * Otherwise scattered around the board, following the "coffee cup" rule-- If you wave a coffee cup over your board, there should be at least one bulk capacitor under it for each power-supply voltage in that area. John Barnes KS4GL, PE, NCE, ESDC Eng, SM IEEE dBi Corporation http://www.dbicorporation.com/ ------------------------------------------------------------------ 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