Fundamentals of Signal Integrity

Whether the creative juices weren’t flowing or I just didn’t make the time,   I’ve been on a bit of a blogging hiatus for the last month.  Hopefully the ball is rolling again with this post and I can get back to a regularly scheduled program.    My last blog post was introducing the concept of being a professional.  I asked some “could it…” questions at the end of the post with regards to a company who is able to get designs out the door, but could they be better at what they’re doing?  And if they could be, what steps do they take to get better?

The reality is that we can all get better at what we do.  No matter how good we are (or we think we are) at something, there is always room to grow.  I’ll take my daughter as an example – she’s almost 2 going on about 12.  She can speak exceptionally well…..for a 2 year old.  While you can understand most of what she says, she has a long way to go to speak more eloquently than “I want milk pweas”.

For her, where she’s at right now in life, that’s the best she can do.  And maybe that’s not so different from you – for you, you’re doing the best you can where you’re at in your job, career, project, etc.  But, just because it’s the best you can do right now, doesn’t mean this is as good as you’re ever going to be.  My daughter will continue to learn new things and develop her brain, skills, and language.  As an adult and designer, don’t let yourself fall into a trap of stifling  growth.  Old dogs can learn new tricks – it’s just harder to learn and it helps if the tricks are easy.

My hope is that I can teach you some new tricks and tips that you can use as you design.  Over the next few posts, I’m going to try and outline a methodology for doing signal integrity aware design.  What’s that mean exactly?  It means I’m going to get back to basics:

• How do I select nets for analysis?
• What’s critical net length?
• What’s the best way to design a stackup?
• How do I know if my net needs a termination and what kind should I use?
• What interfaces cause the most problems?

The list goes on, but I plan to try and address the most common questions when it comes to designing with signal quality in mind.  If you have any ideas on topics or questions you want answered, just post a comment and I’ll address it in a future blog. Look for the first post in the series to come sooner, rather than later – I promise!