Signal integrity evangelist Eric Bogatin makes us think about what happens to step signals as they travel through conductors.
For years, we've been hearing how the edges of digital signals make every PCB trace into a transmission line. Where there's plenty written about the subject, those who teache signal integrity always get an audience. At DesignCon 2014, Signal Integrity Evangelist Eric Bogatin packed the Chiphead Theater with his educational and entertaining talk about what happens to step responses as they travel along a PCB trace. If you heard Eric's talk, then you should have no trouble answering this week's quiz questions. As always, answers appear on the last page. The images are for illustration only should not be used to derive your answers.
1. A 1-V step edge is launched into a 50 Ω transmission line. What is the voltage that would be measured at the far end when the step edge gets there, if the end is open, shorted or terminated into 50 Ω?
- Open = 1 V, short = 1 V, load = 1 V
- Open = 1 V, short = 0 V, load = 0.5 V
- Open = 2 V, short = 0 V, load = 0 V
- Open = 2 V, short = 0 V, load = 1 V
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