John, one more stackup if you don't like running traces on the top and bottom layers: John, there are many ways to go. Here are two 8-layer stackups that should work well: GND SIG PWR1 SIG SIG PWR2 SIG GND Spacing between layers is be as small as 6 mils. The internal traces on layers 2 and 7 are 5 mils wide. The internal traces on layers 4 and 5 are 7 mils wide. The spacing between layer 4 and layer 5 is 20 mils for a 63 mil board thickness. If you provide GND flood on the SIG layers, the PWR plane impedance will be low. The PWR layers can be run close to the edges of the board if you stitch the GND planes together with vias every 1/4 inch. Dave Cuthbert
From: [email protected] mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, December 08, 2004 3:38 PM To: [email protected] Subject: Design for emc and pcb stack-ups Hello, I am embarking on an electronic design for a cctv camera that will employ 8 or 10 layer PCB. It will include a high speed DSP (400-600MHz internal clock) that requires both 3V3 and 1V2 supplies I am considering employing dual power planes rather than segment a single power plane. I would appreciate any feedback on... reference material that outlines pros/cons of either solution single or dual plane. Material describing stack options for optimum emc - 8 or 10 layer? Most of the references I have reviewed do not directly address dual power layers in the stack. Any comments appreciated. Thanks John Coyle Senior Engineer Video Systems 6554 - 176th Street Surrey, BC Canada V3S 4G5 _____ Honeywell 604.574.1526 x8633 [email protected] 604.574.8523 Fax ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
