Recently, a discussion flared up in our office after someone questioned the use of the term ‘trunk routing’. They wondered whether it’s really a term in its own right – or just a fancy name for bus routing? The question was raised by someone who’s not that familiar with our high-speed design tools – so we’ll let them off the hook! But it begs the question: do people really understand the difference between the two?
How To Overcome Design Challenges Associated with Gigabit Signalling and the Ubiquitous LVDS in High-Speed PCB Design (Part 1)
Over the next few weeks I’m going to talk to you about the high-speed design challenges associated with Low Voltage Differential Signalling (LVDS) and how to overcome them. Today I’ll start by mentioning some applications of LVDS and some basics about how it works. Next week I’ll share my knowledge on effective and efficient PCB routing of LVDS signals.
Why would you as a PCB designer take on this task of signal integrity screening? Clearly, I am suggesting adding to your already compressed schedule – I can’t deny that fact. And by performing this action, we are departing from traditional placement and routing activities. But hold on, before you switch off – when proposing this action to designers, some have actively told me that they want to increase their value in the design process. Others desire a better understanding of the effects of their routing choices, and a few totally embraced the idea on its own merits – the overall time and money savings for the organization.
You could pick up any PCB or electronics design magazine and probably at least one article will be devoted to some aspect of high-speed digital design; be it routing techniques, signal integrity analysis, electromagnetic compatibility or power integrity. This has now become a mainstream design practice.
Are you one of the many designers developing today’s complex PCBs? Those containing high pin count ICs like FPGAs or new microprocessors sharing multiple voltage rails? If you’re anything like the people I’ve been talking to recently, you might be suffering from time-consuming and costly problems in supplying the chips with power over the required frequency range. Yep – you’ve got a Power Integrity problem.