Mastering the TDR Webinar Series with Dr. Eric Bogatin


Mastering the TDR in 45 minutes
With Dr. Eric Bogatin

Mastering the TDR Webinar Series with Dr. Eric Bogatin
Teledyne LeCroy introduces a unique 6-part webinar series on Mastering the TDR. While the TDR has been a workhorse instrument for characterizing interconnects for fifty years, it is often under-utilized because the principles are often confusing. This webinar series reduces the confusion and arms attendees with the skills they need to get the most out of performing TDR measurements and extracting useful information.

If you have a TDR, this webinar series will offer you the recommended best measurement practices to get the most out of your TDR. If you don't know about the TDR, this webinar series will show you how it can reveal the impact of physical features on the electrical performance of cables, connectors, circuit board traces, and other structures. Both single-ended and differential interconnects are explored.

Part One: Mastering the TDR in 45 Minutes
The workhorse instrument used to characterize all PCB traces is the Time Domain Reflectometer (TDR). Its measurements are often mis-interpreted because the impedance properties of transmission lines are confusing. In this webinar, where we will show you the right way to think about signals on transmission lines and how to interpret TDR results. Using live measurements, we’ll look at some cool examples of the properties of real circuit board traces. Watch now >>

Part Two: Taking the TDR for a Spin: Interpreting Impedance Profiles
The TDR measures instantaneous impedance. When the interconnect is uniform, we can interpret the instantaneous impedance as a characteristic impedance. When it is not uniform, the instantaneous impedance depends on the rise time of the TDR. We can still use the impedance at a rise time as a figure of merit. In this webinar, you will learn how to interpret a TDR’s measured instantaneous impedance profile in terms of the interconnect’s characteristic impedance and time delay, and the location of impedance discontinuities. We’ll look at a variety of cables and PCB interconnect structures. Watch now >>

Part Three: Differential Impedance: How Not to Be Confused
Differential pairs proliferate in all high-speed interconnects. While many of the principles of single-ended interconnects can be applied to differential signals and interconnects, there are a few special considerations that are different. In this webinar, we explore how to think about differential and common impedance. Based on the properties of a differential pair, we look at using a two port TDR as a differential TDR so we can characterize the basic differential impedance properties of the interconnect. Dr. Bogatin will show a variety of examples of differential traces on circuit boards and cables. Watch Now >>

Part Four: Differential Pairs with no Return Paths
Controlled impedance single-ended transmission lines always have a return plane in close proximity. Otherwise, they are not controlled impedance and they make terrible single-ended interconnects. But a return plane is not necessary for a differential pair. Unshielded twisted pair (UTP) cables have no adjacent return plane yet they can make great differential interconnects. In this webinar, Dr. Eric Bogatin will explore how this is possible and discuss best measurement practices for differential impedance when there is no adjacent return plane. Watch Now >>

Part Five: Analyzing Discontinuities with a TDR
When the instantaneous impedance is flat, we interpret the TDR response as the characteristic impedance of the interconnect. When the instantaneous impedance is not flat, but a peak or a dip, we describe the structure as a discontinuity. Its min or max impedance depends on the rise time. In this webinar, Dr. Eric Bogatin will explore how to think about the discontinuity as a short transmission line or as an excess inductance or capacitance. This is the first step in building a circuit model for the interconnect or “hacking” the interconnect. Watch Now >>

Part Six: Advanced TDR Concepts
A TDR can measure much more than just the impedance profile of a transmission line. In this webinar, Dr. Eric Bogatin shows how to use a TDR to measure the dielectric constant of a laminate, the excess capacitance or inductance of a discontinuity, the return loss of an interconnect with a matched termination, the resonant frequencies of structures and the impedance uniformity of a flex circuit or interconnect with high series resistance. When your needs require higher bandwidth, more ports, cross talk, insertion and return loss measurements, he’ll introduce you to a more advanced instrument to meet your most demanding needs. Watch Now >>