At 02:19 PM 6/5/2002 -0400, Mitch Berkson wrote: >Just as a point of interest - the type of guard trace I will be using is not >necessarily connected to ground. It is guarding the high impedance input of >an op amp with a low impedance signal at the same voltage in order to minimize >leakage current into the high impedance node.
If this guard signal is used only once, i.e., only guards one trace, and is not used elsewhere, then there would be not so much need to use the techniques I mentioned. But if the existence of loops in the guard would be harmful (which I don't expect from Mr. Berkson's description), then one might wish to exert more control, with something like what I suggested. Even with guarding a single trace, it might be useful to use virtual shorts, one at either end of the trace (or one pair at either end). This would force routing of the parallel signals, though it would not guarantee it parallelism, because of the absence of a signal pair rule as I mentioned before. Just to mention it, one method of routing a trace plus guard is to route the trace, originally, as a trace fat enough to cover the final size trace plus the guard(s) plus gaps. Then the trace could be shrunk with a global edit to the final size and outlined quickly with the outline tools. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 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/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
