I'm presently having an EMI problem with dot clock emissions from a PC video
card. Adding additional ground layers isn't an option since I'm already at
the maximum. The return plane is connected to the chassis on this card and
the video cables are very good. The emissions are coming right out o
!
Anyway, good luck with the design.
Regards,
tony_fredriks...@netpower.com
--
From: Max
To: Tony Fredriksson
Cc: mkelson; emc-pstc
Subject: Re: Need EMC Help With Video Card
List-Post: emc-pstc@listserv.ieee.org
Date: Friday, August 30, 1996 12:11PM
Tony,
Thanks for the great ideas!
Tony,
Thanks for the great ideas!
%>
%>Hi,
%>One way to do this would be to line the gap with decoupling caps
%>in the vicinity where the traces cross, on either side of the gap. The
%>values of the caps would be chosen so that they self-resonate
%>(due to self AND via series inductance) in th
e concerns may not be your
problem at all and changing all of this may not help. But hey,
consider the advice worth what you paid for it!
Regards,
tony_fredriks...@netpower.com
--
From: Max
To: Tony Fredriksson
Cc: emc-pstc; mkelson
Subject: Re: Need EMC Help With Video Card
List-Po
Mike,
Thanks for the information. I wish I had tried moving the wires against
the chassis or putting ferrites on the fan wires.
I'm not sure what I could do about this from a practical view point,
though, except to look for another PC. I doubt if the FCC would allow
you to modify the PC.
Max
On Aug 29, 10:19am, Max wrote:
> Subject: Re: Need EMC Help With Video Card
>
> I still have the problem when I remove all of the
cables from the system,
> including the printer cable, etc. The emissions are
coming out of the
> holes in the PC cabinet and this is a very good
%>
%>
%>Max,
%>
%>At what frequency or band of frequencies is the problem occuring?
Our video clock operates at 126 Mhz. The frequency synthesizer seems to be
deriving this from a 31.5 Mhz clock, so it produces harmonics at 31.5,
63.0, 95.5, 126.0, 157.5, 189.0 220.5, 252,0, 283.5, 315.0, 346.5,
ign off of.
Thanks,
tony_fredriks...@netpower.com
--
From: Max
To: emc-pstc
Subject: Need EMC Help With Video Card
List-Post: emc-pstc@listserv.ieee.org
Date: Wednesday, August 28, 1996 9:24AM
I'm presently having an EMI problem with dot clock emissions from a PC video
card. Adding ad
are my
own and do not necessarily reflect those of my employer.
__ Reply Separator _
Subject: Re: Need EMC Help With Video Card
Author: Max at internet
List-Post: emc-pstc@listserv.ieee.org
Date:8/29/96 12:44
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