Dive into an in-depth video lecture on PCB track impedance and Time-Domain Reflectometry (TDR) presented by Eric Bogatin. Explore key concepts such as characteristic impedance, reflections in PCB tracks, and the reasons behind using 50-ohm impedance. Learn about differential pairs, closely and loosely coupled differential impedance, and how to conduct TDR simulations and measurements on various PCB tracks and coaxial cables. Gain insights into the practical applications of TDR in PCB design, understand when small impedance changes matter, and discover why ground is sometimes removed under pads. This comprehensive presentation offers clear explanations and demonstrations to enhance your understanding of impedance in PCB layout, essential knowledge for every PCB designer.