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Isolating digital noise from micro controller based clocking

Posted: Mon Feb 13, 2017 11:39 pm
by MacroMachines
We have a design making use of a micro controller for the FV-1 clock input, and have encountered some digital noise artifacts. I am wondering if there are any good resources as to the best method for addressing this. I have been reading a bit on digital / analog ground splitting which seems relevant, and mainly was curious if there was potentially something more specific showing an FV-1 based design schematic / pcb that makes use of a micro controller or other non-chrystal clocking techniques.

Posted: Tue Feb 14, 2017 12:50 pm
by Digital Larry
Look at the Fixed Program module here: http://www.spinsemi.com/mixer_application.html

Though I have no experience with it to know whether it effectively suppresses uController noise.

Posted: Tue Feb 14, 2017 2:38 pm
by frank
Good ground is very important. You can get away with a single ground plane but you must watch for ground loop and path issues. Any trace should have solid ground below it, do not run a trace over a break in the ground plane. Keep traces short and straight as possible, if you have traces on 2 layers of a board make sure they cross each other and not follow right over each other.

Posted: Sun Feb 19, 2017 10:08 am
by MacroMachines
frank wrote:Good ground is very important. You can get away with a single ground plane but you must watch for ground loop and path issues. Any trace should have solid ground below it, do not run a trace over a break in the ground plane. Keep traces short and straight as possible, if you have traces on 2 layers of a board make sure they cross each other and not follow right over each other.
EDIT: realized you meant parallel vs perpendicular, assuming so the signals aren't near each other for long traces along the opposite sides of the board. Is this like an induction/Magnetic interference thing? I truthfully could use some substantial pcb design insight.

Are there good books or tutorials etc you might recomend?

Original:
I'M not sure if I understrand. W머 ㅗㅕㅏ몀ㅑㅣㅣㅣㅣㅣㅏㅏㅒㅖㅐㅛㅐㅆㄳㄲㅆㄲㄷㄱㅆㄲㄷㅈㄷㄱㄷㄱㅂㅈㅛㅛㅐㅖㅣㅣㅣㅣㅣㅣㅏㅓㅗㅓㅏㅓㅑㅓㅏㅓㅏㅗㅒㅗ쏫ㄷㅆㄱㄷㄱㄷㅅㄷㅆㅂ뱨뱨뱨ㅃ도도도도도ㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㄹㅇㅀㅎㅎ여ㅏㅓㅏㅣㅣㅎ
What do you mean by "make sure they cross and not follow right over each other"?To me those sound like the same thing, signals on separate traces that are near each other? MDoes it help substantially to have maybe a 4 layer board with ground plane in the middle?

Posted: Sun Feb 19, 2017 11:11 am
by frank