Remember when 50-MHz clock signals were state-of-the-art?

-October 09, 2007


Everyone knows that time and frequency are inversely related, but I claim that you can measure time by the frequency of the signals in your circuits. The lower the frequency, the longer time has passed since you worked on it. Remember when 50-MHz clock signals were state-of-the-art? Today, 50 MHz is child's play in the face of 3-GHz clocks, 10-Gbit digital data streams, and microwave signals that approach 100 GHz.

"Below a Gigahertz" (listen to the song) reflects on today's problems with high-speed signals and how they make yesterday's signal-integrity problems seem trivial. The song grew out of my March 2007 article "Offensive channels."

In that article, Bagdan Gavril, director of engineering at Elma Bustronic said "at frequencies above 1 GHz, you have to pay attention to mistakes in board design that aren’t important at lower frequencies." Gavril and others I interviewed for that article indicated that above 1 GHz, you enter a new world where every PCB trace is a transmission line, vias act like stubs, and digital engineers need RF experience to do their jobs.

"Below a Gigahertz" was recorded at Melville Park Studio, Boston, MA.

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