Issue link: https://iconnect007.uberflip.com/i/750006
30 The PCB Design Magazine • November 2016 Editor Andy Shaughnessy recently sprung a request on me: Would I like to write an item on vias? A complex and tricky subject, I thought. But after some reflection it seemed like a good idea…so, here goes. I was just about to leave for PCB West in September, and my connecting flight developed a fault. Always better when the plane breaks on the ground than in the air, but inconvenient nevertheless. If you want to be certain to catch your long-haul flight, says the ground agent, you must go via London Gatwick. I'll cut a long story short, but I had 10 min- utes to decide. Should I, on the one hand, get to London Heathrow via London Gatwick, or take my original connection which maybe will, maybe won't, get me to Heathrow in time for my connection? I bit the bullet, had my bags offloaded and started the process of looping through security and booking a new flight on an alternate airline only 45 minutes before de- parture whilst at the same time trying to book an overnight hotel whilst going through secu- rity to the new flight. In the process, I became one of those annoy- ing people who is on the phone at the gate and up the jetway. I did try to book online but that's a mare too when you are in a rush. Still, I got the last room available close to the desired terminal. What's all that got to do signal integrity? Well, it's a lot easier to go somewhere by a direct route than via somewhere else. The same is true for signals. The best a designer can do is to en - sure the via offers the least inconvenience to the signal; otherwise it's going to end up at its desti- nation a bit grumpy and battered out of shape, just like I was when I boarded the aircraft for the long-haul flight the following morning. Though by Martyn Gaudion POLAR INSTRUMENTS Vias, Modelling, and Signal Integrity FEATURE COLUMN: THE PULSE