[SI-LIST] Re: Chassis and Signal ground
- From: Chris Cheng <Chris.Cheng@xxxxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Wed, 15 Dec 2004 18:16:45 -0800
One thing worth checking before you decide on your strategy is to check your
add-ons like disk drive or I/O card grounding. I've seen many systems that
implement single point connection at backplane only to discover that their
disk drives or I/O card shorts the logic ground to their chassis. That would
make your noise shows up in unexpected places to say the least.
-----Original Message-----
From: Peterson, James F (FL51) [mailto:james.f.peterson@xxxxxxxxxxxxx]
Sent: Wednesday, December 15, 2004 8:16 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Chassis and Signal ground
Chassis and Signal ground, what happens to our noise susceptibility if we
connect them together on our cards (some of them are analog cards)?
We've always kept chassis ground and signal ground separate on our cards and
connected them together on our backplanes. The reason we even have a chassis
ground on a board is because we use them as thermal layers that are used to
remove heat from boards (that need to operate in the vacuum of space).
We are currently evaluating connecting our signal ground on the boards to
the "card guides" of the chassis. The benefit is we don't need thermal
layers anymore. The signal ground layers can now conduct the heat out
through the guides and onto the chassis....but what have we done to our
radiated noise levels and to our susceptibility to incoming noise?
Regards,
Jim
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
