Latest Posts

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 cle...

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

What is Signal Integrity?

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 Integrity from angles not typically articulated. My statement...

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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 susp...

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

Simulating a Serial Link

Author: Donald Telian , SI Guys - Guest Blogger And now one of my favorite topics: simulating a serial link. Good technology, good models, good margins, endless options. Yet how do I construct an accurate simulation? And what do I measure? Part of what makes this topic interesting is the variety of answers out there. And the almost infinite number of dials makes the task an engineer’s dream. In a world like that, how do I get started? …and how do I know when I’m done? How good ...

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Donald Telian, SiGuys - Guest Blogger 4/15/2019 Comments(0)