FAQ

What does SIEMC mean?
Originally the URL of the website was Signal_Integrity-Electro_Magnetic_Compliance. That was shortened to SignalIntegrity-EMC. That was shortened to sigintemc. If you give out your email and website more than half a dozen times, you realize that fewer letters in the URL the better. Hence it got shortened to SIEMC. Many think the name of the company is SIEMC.com when it is really Terry Fox & Associates.

How can you get the design right the first time EVERY TIME?

That is a very good question. To answer that you must understand the various segments of the design world. As I see it, they break up into three areas .


The first segment is the leading bleeding edge of technology. That is primarily the domain of the silicon vendors. Someone needs to invent the technologies that the rest of us will use to build products. Those new technologies will eventually be enshrined in a JEDEC standard. Until they get everything figured out and documented, it will be strictly a trial and error process. I have no answers for this segment.


The second and third segments of the design world are using industry standard technology. The technology is documented. The parts can be simulated. The pieces of the design are predictable because of the work of the technology inventors. Once pieces are documented and predictable, we can get it right the first time simply by applying an appropriate amount of rigor in our design process. If you are doing small volume production, it makes sense to add some insurance money to the manufacturing cost in order to minimize the design cost. If you are doing large volume, it makes sense to add some design cost in order to minimize the production cost. Regardless of whether you are doing high volume or low volume, you can use appropriate design methods and validation strategies to arrive at a design that will work right the first time well over 95% of the time.


Ok. So what is the 5%. That sounds like lawyer weasel words. Well you are right. It is lawyer weasel words. Occasionally you will get a part that does not meet its published specification or you will be forced to use a part that is inadequately specified. In either case we are rolling the dice and hoping to get lucky. The second issue is getting a design where marketing wants you to reduce the price on the manufacturing cost so far that the resultant structure can not be simulated precisely enough to know if the design will work reliably when placed in production. Just because you can get one working in the lab does not mean you can produce it in quantity. You need to understand the accuracy limits of your analysis and design in a manufacturing tolerance to assure high manufacturing yield.



Why do you use Mentor HyperLynx in the class? Is this really a tool infomercial that you are asking me to pay for?

No. This is a design methods and validation strategies class that is tool chain independent. I explain the process. It is up to you to use that process with the tools of your choice. However, not all tools are equal. The key attributes of a useful tool are, one, the tool must give you the correct answer and, two, the tool must be easy to understand and easy use. A typical designer will be deeply enmeshed in SI, PI, and EMI issues about once every six months. If the tool learning curve is steep, this becomes very difficult. You waste too much time getting back up to speed. HyperLynx is extremely easy to use. If you understand the problem, running HyperLynx seems obvious. As a result, I can explain the physics of high speed system design without getting bogged down in tool issues.

Aside from the accuracy and ease of use issue, Mentor loans me simulator licenses for the class. Mentor offers my students the use of the full up simulator for a week so they can do the post class simulations. Mentor let's me use their offices throughout the world to hold my classes. Mentor and their distributors help promote my class. HyperLynx works well with every serious PCB design tool chain with which I am familiar. I have used many tools over my career and I am a big fan of HyperLynx. I am not saying that other tools do not work. I just can not vouch for them, because I seldom use them.

The material I teach is applicable to any PCB layout and SI PI simulation tool set. The methods are universal regardless of tool chain.