February 2011 Issue

Winter Days

Letter from the Editor

Dear Friend,

Christmas break went by fast this year so here we are in 2011 and I hope all of you had a great year!

I've been pretty busy behind the scenes the last couple of months and I'm looking forward to 2011! I've been beta testing our new SharkSim PCB application and I think it's going to provide just the right features for everyday Signal Integrity analysis so stay tuned for more.

I'm also going to start the Signal Integrity webinar series back up again this year and I'm looking at adding some virtual training opportunities as well so that's going to be an exciting new addition to 2011.

I have a special guest interview this month as I try to highlight other companies and products that are useful to hardware engineers. This month I talked with Al Neves from Wild River Technology about their new channel modeling platform which sounds interesting especially if you are working with S-Parameters so be sure to check out the full interview below.

We are getting another 16+ inch storm here in Portland, ME so to my other friends in the Mid West and East Coast don't throw your back out shoveling this week!

Best Regards,

Timothy Coyle, President, Signal Consulting Group LLC

Custom Signal Integrity Classes

Signal Consulting Group Updates

I'm getting interest in holding customized Signal Integrity classes for companies and that got me thinking about what would be the best material to include in a custom Signal Integrity class for a group at a specific company. I can use my SI Rock Star class as a starting point but I'm sure I am missing things that other people think are important.

So I setup a quick poll on LinkedIn that you can vote on if you would like to have a custom class in Signal Integrity and then put in the comments what topics you would want to be included. Be as general or as specific as you want. If I get enough response I'll tabulate the answers and include them in the next newsletter.

Take the Poll »

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Beta,Beta,Beta

SharkSim News

I have a few early customers using our new SharkSim PCB application so I guess it's really out of beta now but with the coding I'm doing it doesn't feel like it! I'm finishing up an update to make differential signals easier to simulate and graph and then I'm off to do some IBIS-AMI/SerDes research.

Look for a new website re-design in the next few weeks to highlight the differences between Developer and PCB along with some new videos as well.

SharkSim Overview »

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Atmel Road Show

Embedded Design

I'm hoping that I can attend the event coming up in the Boston area but Atmel is doing a roadshow bringing two different hands on sessions to a city near you! The touch technology seminar looks the most interesting to me and each seminar is only $99 per person for a full day of training with Atmel rep and you get a design kit!

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Wild River Technology Interview

High Speed Digital Design

I had a chance to talk with Al Neves of Wild River Technology about thier new channel platform modeling product and below is excerpt from the email interview. If you're interested in having your company or product highlighted contact me and we can see if we can get you in a future issue of Signal Bytes!

Tell us a little about yourself and your company

My prior experience consists of numerous start ups focusing on capital equipment, semiconductor design, and applications for high speed measurement. Jim Bell and I worked together for the past 6 years mainly focusing on signal integrity consulting, and high speed system design. We started Wild River Technology LLC last year since we were developing products that were successful, but had no corporate structure or cogent marketing plan. Our early products immediately hit a sweet spot with the S.I. community due to issues with correspondence, jitter, measurement challenges.

Give us a brief overview of your channel modeling platform product

This product represents a logical progression of an early beta physical layer product design called Physical Layer Reference Design (PLRD-01). This was a product with 30-some structures that provided superb TRL/LRM calibration, and numerous single ended structures. The new design, Channel Modeling Platform or CMP-08, is intended to not only serve the PLRD functions, but adds a host of differential structures ranging in low to high loss. We have also included some very interesting crosstalk structures. LeCroy Corp. was our first customer for this platform and we co-authored a paper with them for this upcoming DesignCon.

S-parameters are becoming a part of daily life for all of us but can be confusing and time consuming to understand how to generate and use them properly. How can your modeling platform help engineers deal with S-parameters?

Frankly, most of the measured S-parameters we see, even from large established companies, are commonly plagued with issues. They are not causal, not sampled correctly, have major passivity issues. This wreaks havoc on not just the system level simulation results but in some cases makes the simulator blow up. We provide S-parameters for known structures on this platform so you can first measure those and insure passivity/causality, and compare the S-parameters to the provided S-parameters. We also offer metrology training as an option.

What are the bench marking capabilities of the modeling platform and how can they be used?

The single worst mistake folks make when they are benchmarking, say a jitter RJ/DJ extraction or maybe TDR versus VNA measurements, is that they use typical encountered structures that are close to 50ohms (or 100ohms differential). The CMP-08 provides a host of structures that range in impedance and loss. An example of an "atypical" structure, or a structure you wouldn't intentionally design, would be a resonator stub. There are numerous numbers of these on this platform. Resonators generate very predictable insertion and return loss S-parameters and represent a key benchmarking tool.

I am a big proponent of validating your simulation tool flow and you also offer 3D model kits for your modeling platform. How can these be used in a company's simulation flow?

You are definitely right with 3D EM correspondence. The CMP-08 is delivered with the Allegro design file and geometries of all the structures so you can, in minutes, import them into your solver, extract, and perform meaningful correspondence in minutes. Our customers are finding this to be very valuable.

There are also significant issues with pre and post layout correspondence. The DesignCon paper addresses this. In the pre-layout stage you typically only have the board vendors values for Permittivity and Loss Tangent. Unfortunately, these values are only marginal for high confidence design. The CMP-08 platform provides hooks or structures that show you easily how to collect this data and then create a verifiable loss model, such as Wideband Debye model.

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2011 Training

Training & Events

I'm still working on putting together some new training material for 2011 that is going to include online videos and webinars. I was leaning towards doing pre-recorded webinars late last year but decided that those are pretty much online videos so I'm going to keep doing the live webinars this year and see how the feedback goes. I should have a new webinar to announce next month so stay tuned!

For those of you that missed the PCB Impedance Stackup webinar or some of our other webinars this past year you can view the archived webinars online.

View Archived Webinars »

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