The small spacing has nothing to do with EMI. It has to do with creating a large value, high performance capacitor to supply switching currents. Lee DORIN OPREA wrote: > Hi everyone, > > In high speed design we often use the split planes on a power layer. The > spacing between the digital planes is correlated with the distance > between the power layer to the ground layer. In general we have 50 mil > spacing. It just happen to run into a different opinion which recommends > a very small spacing due to the slot antenna effect (the gap between the > planes) that allows the eddy currents to radiate. A small spacing may > couple noise into the low power supply (1.5V or 1.8V). > How critical is this radiation effect versus noise coupling between the > two power distribution systems ? > What is the practice out there ? > > Thanks very much for you guys always being there, > Dorin > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > 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 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