Carson,
Sounds like you need quick answers in a condensed way. I suggest the book "High
Speed Digital Design: Design of High Speed Interconnects and Signaling". Amazon
sells an e-copy. It covers many topics in a "get to the point" format in my
opinion.
Best of luck,
Ryan
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Carson Au
Sent: Thursday, November 3, 2016 3:20 PM
To: John
Cc: Lee Ritchey; Loyer, Jeff; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: HDI and SERDES Channels
For example, let's just say some pedestrian 10Gb/s channels.
Are layer-transition via anti-pads important at those speeds? Can I generally
eliminate anti-pads for these channels to gain better routing density?
If via stubs manifest themselves as losses on the channel, can I not care about
these stubs because now the SERDES receiver can recover from extreme losses in
the channel?
On Fri, Nov 4, 2016 at 7:10 AM, John <johndp@xxxxxxxx> wrote:
What is and what isn't important in your design is largely dependant
on the speed you want to go. So giving the list an indication of the
operating bit rate of your Serdes will enable us to better answer your
question
Regards
John
Sent from my Sony Xperiaâ"¢ smartphone
---- Carson Au wrote ----
If loss isn't usually the problem, does that mean usually smooth
copper usually doesn't have to be considered in the design (or are
there more benefits to smooth copper than just lower loss?) Lee, what
are the top problems in modern SERDES layout in your opinion (besides
the fibre weave effect)?
On Fri, Nov 4, 2016 at 3:21 AM, Lee Ritchey <leeritchey@xxxxxxxxxxxxx>
wrote:
Before I would do any of that, I would do some analysis to see whatthis
the losses would be if normal striplines are used. My experience is
that
extra work would not be necessary.but
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx]
On
Behalf Of Loyer, Jeff (Redacted sender "jwloyer" for DMARC)
Sent: Thursday, November 3, 2016 8:16 AM
To: carson.au@xxxxxxxxx; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: HDI and SERDES Channels
I think you'd have to void the layers above or below your signal traces.
For instance, I can imagine routing the longest lengths on the
outermost layers of the "core" of a build-up stackup and voiding
layers above those traces to allow me to widen the traces (they
would also be relatively thick, further lowering loss). You'd want
a solid plane above them somewhere,
it doesn't have to be the adjacent layer. You'd also have to beto
careful
specify smooth copper on those layers, else the manufacturer willprobably
undo your great efforts by putting rough copper on them.control
Jeff
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx]
On
Behalf Of Carson Au
Sent: Thursday, November 03, 2016 5:07 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] HDI and SERDES Channels
Hi Experts,
From my understanding, HDI build-up layers require thin prepreg
layers, leading to very thin trace widths for 100ohm differential
impedance
- and your high speed serial links would suffer great conductor loss.either
How do you mitigate against this?
If your design has many build-up layers with thin build-up layers on
side of your stripline, then it is impossible to even get something
like 100um (4mil) trace widths for your 100 ohm differential pairs!!
Regards,
Carson
------------------------------------------------------------------
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
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 forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
