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On Exercising Engineering Judgment

Author: Donald Telian , SI Guys - Guest Blogger Signal Integrity Engineering requires Engineering Judgment. The same thing that makes SI require Creativity causes it to also require above average Judgment; namely that you will consistently be asked to craft clear answers from insufficient data based on ill-defined measures of success. There’s no way around it, Engineering Judgment Required. So we’ll address this topic here in our mini-series on the soft skills required for Signal I...

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Donald Telian, SiGuys - Guest Blogger 11/8/2019 Comments(0)

On Working WITH Your Layout Engineer

Author: Donald Telian , SI Guys - Guest Blogger I have a distant cousin who spent his career doing high-speed PCB layout. At a family gathering we were learning what each other did for a living, and when he learned I’m in Signal Integrity he looked at me warily. I was one of those guys. He then shared how we was going crazy routing, re-routing, and re-routing a high-speed PCB because an SI Engineer was giving him constraints that were impossible to meet. Lots of time wasted, and he was c...

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Donald Telian, SiGuys - Guest Blogger 10/8/2019 Comments(0)

What is Signal Integrity?

Author: Donald Telian , SI Guys - Guest Blogger Great question. Now that I’ve devoted well over 30 years to the field, I’ll venture an answer. My simplistic definition has always been the analog side of digital. I still like that description, because in practice the binary world of ones and zeroes only exists in theory. And, hopefully, in system memory - assuming the interface’s Signal Integrity SI was done correctly. My answer to the question will describe Signal Integri...

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Donald Telian, SiGuys - Guest Blogger 8/5/2019 Comments(0)

The History of IBIS

Author: Donald Telian , SI Guys - Guest Blogger Every time I sit down to simulate a PCB, quickly download IBIS models and produce meaningful results in minutes, I am still amazed. I can’t help but think about how things used to be, back when all this wasn’t possible. Not only were simulators slow and cumbersome, component-level device models simply did not exist. True, there were a few transistor-level models around, but using them made simulation even more slow and cumbersome. There...

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Donald Telian, SiGuys - Guest Blogger 7/11/2019 Comments(0)

DDRx Memory Interfacing

Author: Donald Telian , SI Guys - Guest Blogger Memory. Every system has it. Short-term, long-term, 2 nd level, static, dynamic, EPROM, graphic, internal, cache – but, by far, from an SI perspective the most common memory interface is DDRx. Double-Data Rate DDR memory arrived in the late 1990s, and has remained the dominant interface for decades. It has proven to be extensible and, now in its 5 th generation, DDRx has achieved a 20x increase in bandwidth. DDR memory occupies an important p...

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Donald Telian, SiGuys - Guest Blogger 6/4/2019 Comments(0)

Measurement Correlation

Author: Donald Telian , SI Guys - Guest Blogger I believe what simulators tell me. It’s funny because, throughout my career, I’ve met many who don’t. How is it that I somehow learned to trust them? Measurement Correlation. Over the years, taking the time to build, measure, and compare what I simulated taught me what’s good – and what’s not so good – about simulation. I developed confidence in my results and intuition that tells me when they’re su...

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Donald Telian, SiGuys - Guest Blogger 5/8/2019 Comments(0)