hello, i've got a negative (ECL) and a positive (TTL) power plane on a board i'm doing. right now i'm figuring on a matching ground plane for each power supply, spaced close to the rail for switching capacitance. here's the stack i'm thinking of:
critical traces gnd -5.2V noncritical traces noncritical traces +5V gnd critical traces does this seem reasonable? i have some semblance of controlled impedance with each trace layer referenced to a dc plane. other stacks suggestions are welcomed. but i need both the ground planes common to each other. can i EVEN have two planes called GND? is having two ground planes a bad idea? if two ground planes is not a bad idea, then how do i tie them together? NOTE: if i tie them together i would like to do it in a way that doesn't mess up my design rules check. i've noticed that additional vias and traces added to a pcb outside the schematic can make the design rules check flag them. i have another question. this is iffy, but i'm a heathen designer anyway. this is just a proto board, and although i'd like controlled impedance, i don't want to pay for it. SO, what i am thinking is that if i get an 8-layer board at the standard 62 mil thickness, that they are going to be just about forced to give me between 6 to 8 mils between layers, without me ever having to spec it. does this sound right? thank you, miker * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
