Recent Newsletter

PLL Response Time

A PLL is a tracking device. When its input changes, the PLL responds, but not instantly. The time it takes for a PLL to respond to a step change in its input is called the response time. From the response time you can derive the PLL tracking bandwidth.

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SiLab FilmsComing Soon

Dr. Johnson's High-Speed Digital Design Courses Soon To Be Online

Signal Consulting, Inc. has recently finished editing a video collection of Dr. Johnson's course offerings, all filmed in high-definition quality by a professional documentary film crew before a live audience. The collection comprises 36 hours of recorded material, with student handouts and outlines. For those of you who want to use the material for other purposes, we include a full set of instructor powerpoint slides with animations.

We now in the process of selecting one suitable University or Corporate sponsor willing to place the entire collection in the public domain at very low cost to the viewer. If your company in interested in being considered as the sponsor, please email Liz <>.

Keep checking back here, or add your name to our contact list, and we will let you know when the collection is available.


Our archives contain hundreds of detailed, comprehensive answers to complex questions, plus archives of editorial articles written for EDN magazine and other publications.

HSDD Newsletter

The High-Speed Digital Design Newsletter originally evolved as a Q & A forum for students of Dr. Johnson's seminars. Now open to everybody, read more...

High-Speed Digital Design

A Handbook of Black Magic

High-Speed Signal Propagation book coverConsidered the "bible" of high-speed design issues, this book helps engineers who work with digital systems shorten their product development cycles and fix their latest high-speed design problems. read more...

High-Speed Signal Propagation

Advanced Black Magic

High-Speed Signal Propagation book coverAn advanced-level reference text for experienced digital designers who want to press their designs to the upper limits of speed and distance. read more...