High Speed Design Features Growing Forward with Altium and Simberian Partnership

Happy New Year from Altium! In our first article of the year we talk to Roger Paje, VP of Sales and Marketing at Simberian about our recently formed formal partnership and how their highly accurate field solver technology is helping usher in new high-speed design capabilities in Altium Designer such as layer stack, impedance and surface roughness modeling. These enhancements began in Altium Designer 19, were amplified in Altium Designer 20, and you can look forward to more in the future.

Judy Warner: Roger, please tell us a little bit about Simberian and what your role is within the company.

Roger Paje: Simberian develops electro-magnetic simulation software for signal integrity analysis of PCB structures and boards.  Our mission is to provide engineers with accurate results validated through real world measurements with our technology partners.  My role as VP of Sales and Marketing encompasses working with customers and also the signal integrity community to produce software that allows them to verify their designs so they work the first time.

Warner: Recently, Altium and Simberian announced a formal partnership. Will you please share what this has and will continue to enable for PCB Designers within Altium Designer?

Paje: The partnership between Altium and Simberian has a single focus: To make accurate signal integrity analysis available to a broader audience of engineers. This is being forced by technologies such as PCIe Gen 4/5 and DDR4.  Designs that will start to utilize these new standards will have high serial channel speeds. In the case of PCIe Gen 4 for example, individual serial channels will run at 15.75 Gbps. These are major speed levels. It will not be simple in trying to port your Gen3 design to Gen4.  Advanced analysis is required.

Warner:  Beyond modeling circuitry, Simberian has the ability to model PCB laminate materials characteristics. What is the significance of this feature?

Paje: Modeling material characteristics is an absolute requirement at the speeds mentioned previously.   Without getting too technical, as speeds go higher, skin effect starts to proportionately impact the signal because the current uses only the outer areas of the conductor.  The signal then will tend to follow each peak and valley of the outer conductor roughness, hence the need to model it.

This means any signal integrity simulation must start with broadband dielectric and conductor roughness models. Simbeor supports 4 laminate material model identification methods - GMS, SPP, SPP Light and T-Resonator methods. Analysis of predictable interconnects starts with the material models and geometry, and that forms the foundation for the rest of the analysis.

Warner: What capabilities were added in Altium Designer 19 and 20?

Paje: Altium Designer 19 first introduced the Simberian field solver with a limited number of geometries that could be analyzed.  There were some limitations in the loss modeling.

With Altium Designer 20, significant improvements were made so most stack up geometries are now supported.  There was also some work done to match accuracy with measurements, which now include conductor surface roughness modeling.

Warner: Please discuss how these new features will impact Altium’s general user base as well as designers moving toward very high speeds.

Paje: These changes will allow users to comfortably design next generation circuits and get accurate layer impedance and delay numbers all within the Altium Designer environment.  This is a critical starting point in understanding the signal integrity characteristics of your design.

We have more than 10 years’ experience at Simberian in validating the accuracy of our calculations compared to measured results. It is important for hardware engineers to trust the results they get from analysis tools, and we have confidence that our calculations will give design engineers the accuracy they need.

Warner: Since you have been a board designer, what are some practical things to look out for when doing high speed designs?

Paje: Using my own experience, but more importantly using the experience and feedback from our customer base, there are a few characteristics I see in successful design projects versus unsuccessful ones.  Successful projects are able to target their product goals from a blank piece of paper, not trying to “port” an older generation technology design to a newer, faster technology (DDR3 to DDR4, for example). 

Successful project teams also have a set of design rules born through experience. They know what has worked in the past, and more importantly what has not worked. Many PCB designs are incredibly complex these days, and diligence to rules adds a level of discipline needed to realize the design.

Finally, I see successful design teams really need to understand their EDA simulation tools.  It doesn’t really matter which vendor’s tools are being used, but it’s important to do their own due diligence in verifying analysis results against measured data.  I see successful teams are meticulous in validating results.

Warner: Roger, thank you for the insight and for sharing the news of our partnership with Simberian and what benefits that will bring to Altium Users. 

Paje: My pleasure, Judy. We’re looking forward to continued collaboration with the Altium team.