| KNOWLEDGE BASE

A rich source of expert knowledge

Learn from experts in the world of embedded systems

Every PCB Designer Needs To Know This About PCB Track Impedance | TDR | Eric Bogatin

Everything you need to know to understand impedance in PCB layout (and TDR). Clear and easy to understand explanation by Eric Bogatin
Chapters:
  • 00:00What is this video about
  • 00:49What TDR is and what it does?
  • 02:37What is characteristic impedance
  • 04:48Why reflections are bad
  • 10:54Why do we use 50 ohm in pcb tracks?
  • 15:28Are lower impedance tracks more immune to noise?
  • 23:45Can you use any impedance for differential pairs?
  • 27:10What is difference between closely and loosely coupled diff impedance
  • 36:03Experimenting with TDR simulation
  • 48:58Measuring and explaining TDR on a simple pcb track
  • 56:39Can we do TDR on a real board?
  • 1:02:13Measuring and explaining TDR on a pcb track with different width
  • 1:05:53Answer: Why we sometimes remove ground under pads
  • 1:07:49Measuring a coaxial cable with TDR
  • 1:14:51Why you may need TDR are where it is used
  • 1:19:00Do we really need to care about small changes in impedance? When?