Articles by Istvan Novak

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.

Power distribution networks (PDNs) delivering power to ICs in a system need to be thoroughly designed and analyzed in order to make sure any voltage fluctuation on the rail is within the tolerance of every IC connected to that rail.  As ICs on the rail draw power, they generate a voltage fluctuation on the rail.  The PDN must have the capacity to supply enough charge such that the resulting voltage drop is less than the maximum voltage drop each IC on the rail can tolerate.  If voltage fluctuations appear outside IC tolerance limits, a slew of problems can surface such as IC damage, failure, or reduced lifespan.

DesignCon has been a tremendous source of information for myself and for the team I have been working with at SUN Microsystems, which later became part of Oracle Corporation. This summary is an attempt to capture some of the most influential papers from the past twenty years that made the biggest impact on our work.

This paper, presented at EDI CON USA 2017, demonstrates the use of a special probe tip utilized to convert a differential measurement of inductor voltage to a measurement of inductor current. It shows the connection and calibration considerations in the measurement of inductor current, including the digital signal processing algorithms required to compensate for the components in the power supply and the probe tip. It also explains current sharing measurements made in the time and frequency domain using a transient current generator.

Microwave engineers know that sharp corners and right-angle bends have their drawback at high frequencies. So what happens if we go to the other extreme of the spectrum, to DC? Istvan Novak takes a closer look.

We have to use enough capacitors so that the PDN functions properly. At the same time, to keep cost and size in check, we want to avoid overdesign and not use capacitors unnecessarily. Read on for advice on how to find the balance.