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Hi All, I reviewed the na_01_1207 package
presentation from IBM. Overall its great work! I have a few comments. The original KR package models were
developed to represent a worst case performance without giving away IP. Most
of the channel simulations had 1 or 2 pole low pass poles at 7.5 GHz. I agree
these models are not real packages with loss. So I think the package losses IBM
presented are reasonable. It can buy back some margin. There is one more effect that I’ve
seen that is much worse that package IL and that is resonance caused by the
plated though hole (PTH) via in the package, the bga, and 1 or so pF at the
die. In a multilayer BGA package design (page 12) the PTH via does not have to
be near the solder ball. Many designs put this via some were on the run between
the die bump and the BGA. This has a resonant effect that is much worse than
IL. I was wondering if we could get some package models with that effect
included. Package crosstalk data is very useful
for a system designer for specific systems. We have found from a multitude of die
to die analyses that crosstalk power is directly proportional to received
jitter. What was surprising was the correlation between crosstalk power and
jitter was relatively independent of how and where the crosstalk occurred in
package. It sort of brings up the notion of spec budgeting. I could present
this at the up coming meeting. Best Regards, Richard Mellitz, PE, Intel Corporation 803-873-7343 (m) From: John DAmbrosia
[mailto:jdambrosia@FORCE10LABS.COM] Dear Task Force Members, Proposed models for SFP+ host and PMD IC models with accompanying
.s4p files have been submitted by Ali Ghiasi, Broadcom. The data and
reference presentation have been uploaded to the task force public/channel data
area, and may be found at http://grouper.ieee.org/groups/802/3/ba/public/channel.html Best Regards, John D’Ambrosia |