D. C. Smith Consultants
High Frequency Measurement Website
Douglas C. Smith

HF News: Analog RFI, ESD, and More
Issue 3
February 3, 2017
Overview: ESD and analog circuit design seem like different fields within electrical engineerng, but I have some information on both this week. There are lots of engineering links this week, some funny and some informative.
General News: With DesignCon happening in Silicon Valley this week and CES in Las Vegas just ended a few weeks ago, it seems like technical shows are booming these days. This is amazing given tight budgets in recent times. One of the ways shows use to maximize attendance is to locate near a high concentration of potential attendees and locate near good airports. Silicon Valley and Las Vegas fit the bill in these respects. How often do you attend a technical symposium or show? Let me know and I will publish the unofficial results.

What I Have Been Doing: I am continuing to work on a number of new ways to generate and apply ESD to integrated circuits and electronic systems that can head off problems in the field in ways standardized ESD testing cannot. There are a few themes that run through my work in this field:

  1. Overcome the low duty cycle of ESD testing (<10**-7 typically or 100 ns out of one second). This allows faults that show up only in certain system states to be missed entirely during ESD testing. But out in the field where ESD happens all the time, the fault can show up causing field returns or worse, lawsuits.
  2. Overcome missed cases where low to medium level ESD results in accumulating damage over time leading to field failures. Current ESD testing does not address this at all and current ESD test and simulator equipment cannot be used for this type of testing. Note that low level ESD is much more likely to happen in the field than ESD applied to systems and devices in test labs.
  3. Other type of testing I am working on stress systems in various ways to detect hidden design flaws including RF injection locally in a circuit without electrical contact using inductive coupling.

Ever have an ESD problem, even though your design passed official ESD testing, especially in the field? Want to head off a much greater fraction of potential costly ESD problems in the field? Keep tuned!

Useful Links:  RF interference to analog circuits is a big issue these days. Installing filters on cables can fix the problem, but this route is expensive and nowhere near optimum if you have design control over the circuits having a problem.
  1. Link to a typical case of RF interference to an analog circuit:
  2. Here is an example of an RF resistant op amp:
  3. I have shown in the past how to make most any op amp resistant to RF:

Engineering News Links:

  1. Knitted muscles provide power:
  2. Signal Integrity Journal:
Fun Engineering Links: 
  1. Here is a great Dilbert video:
    The interesting thing about it is that I used to take apart TV sets and build ham radio equipment with the parts when I was 12 years old!
  2. Remember your first day in engineering school? Was your second day like this
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And now a word from our sponsor, me that is! If you are interested in finding hidden flaws in your design that may become lab or field disasters, or quickly determine the cause of a field problem you already have, I have developed tools that accomplish these tasks quickly and easily that standard engineering analysis cannot. Many of these tools and techniques are not available in the literature. Most design problems I work on are understood, and even fixed, in a few days, even after weeks or months of effort by in-house resources have failed. Call me to discuss.

Douglas C. Smith
PO Box 60941
Boulder City, NV 89006
Email: doug@dsmith.org
Tel:     702-570-6108
Cell:   408-858-4528