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I have lost count of the number of times I have been asked to fix an EMC problem, only to find that a shielding box has been designed or purchased to provide XdB up to fMAX. Or a filter has been designed or purchased with a similar specification, but to reduce cost the filter has been mounted on a printed circuit board (PCB) inside the box, with a cable from it entering or exiting the box through a plain connector.

For this project, we will use an Atmel 328 microcontroller demo board, prepared with firmware to control it explicitly for our purposes, and with coaxial cables connected between the I/O pins and the input to the active probes of the scope. This interconnect provides a high bandwidth transmission line path for the signals.

If the die's I/O power rails are shared by the core power rails, here's a way to get your core power-rail measurements anyway.

How do you achieve high bandwidth in your measurements while minimizing current load on your DUT? Given that your DUT is a power rail, you really don't want to draw too much current from it., or your measurement system will distort the rail. But these two measurement criteria are at loggerheads with each other. It's a quandary, and it has to do with the fundamental nature of signals on interconnects.

Measuring the noise on a power rail seems to be a straightforward task. However, there are some basic pitfalls that can cause incorrect, or even downright strange, results. Let's look at one of these challenges: RF pickup. We'll demonstrate the effect of RF pickup on a power-rail measurement, and then we'll show you an effective means of mitigating that effect.

Eric Bogatin explains the figures of merit in the time and frequency domain, and he steps through how to get a rough measure of the highest frequency components in a signal.

Eric Bogatin will lead this special session again at EDI CON USA, taking on the topic of how to deliver more than 100A with less than 10 mV of noise to digital devices. See how you can get involved.

Yuiry Shelpnev argues that simulating a link in isolation from the rest of the board (localization) is probably the most important requirement to simulate interconnects predictably. Read on to understand this important concept.

If we know how to design interconnects that correlate with the measurements for 28 Gbps NRZ, is it going to be a "free lunch" to move to 56 Gbps NRZ? Not so easily, as I learned recently. Read on to see how you can benefit from some analysis and validating your tools.

We are usually not worried about having via stubs on power and ground planes and shapes. Does it mean they are completely harmless?  When it comes to potential damage to high-speed signals, power-via stubs can be almost equally as bad as signal-via stubs.  Here is how and why.