Items Tagged with 'TDR'

In this article, Bert Simonovich explores how to avoid “garbage in, garbage out” with field solvers by building an understanding of the nuances of PCB fabrication processes, the interpretation manufacturers’ data sheets, and the tool’s user interface.

If you have designed a controlled impedance transmission line based on a PCB stack-up, how do you know if the PCB fabrication house or another vendor built your stack-up to meet your controlled impedance specification?

SIJ technical editor Eric Bogatin reflects on reflections… “Do corners in traces on circuit boards cause reflections? Of course, they do. Do the reflections cause problems and should you worry? ….it depends.” Read on to see what he means.

Sometimes, when SI and PI worlds collide, we get the best of both worlds. By borrowing a simple impedance measuring technique from the PI world, we have another tool at our disposal to measure true characteristic impedance from a uniformly designed transmission line in the SI world, read on to learn more.

This article explains the steps to use a TDR to measure very small values of inductance and capacitance, including tips for better measurements.

It pains me to say this, but there is such a thing as turning the TDR up too high and it is also easy not to have enough. If there is a “too high,” and a “not high enough,” there must also be a “just‐right,” or Goldilocks, setting. Using measurements, and a smattering of math, the Goldilocks setting answers
will be clear. Read on to find out how.

Transverse electromagnetic waves are used to transmit the signal between components while PPW waves are used to deliver power to the components. Both waves are useful, but they have to be separated. Yuriy Shlepnev, member of the SIJ Editorial Advisory Board, explains why.

Return current for a signal always finds a way to flow as close to the signal as possible, thus minimizing the magnetic energy stored in the loop defined by the signal and its return path. So, the return current path is the combination of conduction paths that together minimize the stored magnetic energy. Some elements of the return current path may be part of the design and other elements may be unintentional.

I received a demo version of a new quick and easy TDR. I decided to take it for a test drive by measuring all the cables I had lying around my lab. The results were surprising!