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First, we asked you to send in your questions for Happy Holden, Joe Fjelstad, Eric Camden, John Mitchell, and Tara Dunn in our “Just Ask” series. Now, it’s Heidi Barnes’s turn! Heidi is a senior signal and power integrity engineer at Keysight Technologies. She has written over 20 papers on SI and PI, and she is an active member in developing the new IEEE P370 standard involving interconnect S-parameter quality after fixture removal. Heidi has been awarded five patents and a NASA Silver Snoopy award (each Silver Snoopy pin flies on a space mission first), and she was named DesignCon's 2017 Engineer of the Year. We hope you enjoy “Just Ask Heidi.”
Q: In the future, what EE disciplines (SI, PI, EMC, etc.) are going to be the most in demand?
A: I am partial to power integrity (PI) because I am now 100% invested as the power integrity product owner for Keysight’s PathWave PI solutions. Signal integrity (SI) is challenging, but even SI needs PI to work. PI is the foundation, and to still find so many conflicting design rules and industry arguments on best practices makes it likely that we will see a growing demand for PI engineers to define best practices and better standardize the industry.
I also like to have an ideal approach to EMC that says if one does the SI correctly so that all Tx power goes to the Rx, and if one does PI correctly and the power delivery is matched to the load, then there should not be any energy going into EMI/EMC. This is rather simplistic, but it does highlight the benefit of good PI and SI designs to reduce the need for additional hardware to mitigate EMC problems.
To submit your questions for Heidi, click here.
Heidi Barnes, Keysight Technologies
Electromagnetic (EM) solvers based on Maxwell’s equations have proven invaluable in the advancement of digital electronics and wireline communications. Plain and simple, electrical engineers need to know what a circuit or electrical interconnect will do when excited by a dynamic or varying signal. In the signal integrity world, an interconnect that passes a DC connectivity check can completely fail at higher frequencies. In the power integrity world, a power rail that measures the correct DC voltage could easily go into oscillation when a dynamic load is applied. Learning the basic skills to fire up an EM simulator, obtain qualitative answers in minutes, and higher fidelity answers in a few days, can be the difference between sleepless nights of product failures vs. robust designs with wide design margins.
Andy Shaughnessy, Design007 Magazine
I recently spoke with Heidi Barnes and Stephen Slater, both engineers with Keysight Technologies, about their presentations at this year’s virtual AltiumLive. They discussed ways to avoid signal and power integrity challenges later by following simple board design practices early on, how SI and PI are interconnected, and why the return path must be more than an afterthought in high-speed designs.
Zachariah Peterson, NWES
Of all the different boards a designer can create, a high voltage PCB design can be complicated and requires strict attention to safety. If not laid out correctly these boards can be safety hazards or can fail to function on first power up, leaving a designer with wasted time and effort. In the best case, the board will function reliably for a long period of time thanks to correct layout practices. High-voltage PCB design can be as complex as any high-speed digital design. Boards for high-voltage systems can be space constrained and they carry important safety requirements. They also need to be highly reliable to ensure they will have a long life when run at high voltage and current.