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An Applications Engineer’s Perspective of IMS2013 – Day 2

On Wednesday, the second day of the IMS2013 show, I had some great observations. There were lots of great questions from engineers dropping by the booth.

The general stream of traffic on the floor was much like the first day but just a bit heavier as it seemed a few more folks probably took advantage of the exhibit only badges for the day. Thus far, the IMS2013 show in Seattle had been going pretty well and the first day of the show brought a good deal of interested engineers by the booth with many great questions. Questions ranged from JESD204B to interleaved converters and back to overvoltage protection on the analog inputs of the converter.

I quite enjoy doing the show each year as it brings on good questions and great discussions. I have the time for a few days to meet face-to-face with many great engineers in the industry and talk about the problems that they are facing in their current and future designs. This is a great way to provide customers with helpful information as well as for me to get feedback and guidance of future products. It is also a great forum for feedback on the support customers receive throughout the year on the products they are using. It is great to hear that they feel very well supported.

Now, let's take a look at some of those questions. Once again, engineers were interested in some of the motivations behind the transition to JESD204B for the converter interface. Since I've touched on that already, we'll take a look at some other questions. It's coincidental that I have been blogging about interleaved converters (and have more to come on that topic by the way). That seems to be another hot topic out there among engineers using high-speed ADCs.

I had some great discussion around the advantages of interleaving as well as what the tradeoffs are. Interleaving multiple converters means that there is more than one converter used. Inevitably, there are inherent mismatches between those converters. There are mismatches in the offset, gain, timing, and bandwidth of the two converters and these have to be considered and dealt with properly. We'll not dive into that deeply here as it takes a bit more discussion to properly explain the concepts (so, another blog, another time). That said, we can move on to the questions on overvoltage protection for the analog inputs of the converter.

This is a great issue to pursue, as to my knowledge there isn't a solution on the market that can be implemented without degrading the linearity performance of the converter. The reason is that clipping devices that would act as limiters are usually diodes which are inherently nonlinear and result in harmonics that degrade the spurious free dynamic range (SFDR) performance of the converter. In many high performance systems today, there is a push to continue to improve the SFDR.

The addition of components that degrade the linearity is definitely not desired. This can be offset somewhat by placing clipping components before the anti-aliasing filter (AAF). This is much better from a linearity standpoint because the AAF can help suppress the nonlinearities generated by the clipping components. This raises a question about the response of the AAF: Is it sufficiently sharp to filter all the nonlinearities caused by the clipping components? I think the best solution is some sort of clipping component that is more linear and doesn't degrade the SFDR performance of the converter. The real question then becomes: Is such a component out there?

So once again it was a great day of questions and very good “food for thought” for both myself and the engineers who dropped by the booth. There were lots of other questions and topics discussed but these hit a lot of important areas with converters today.

These discussions help to drive new product innovations and new design concepts. I feel very rewarded to have had a good second day at the show where great ideas were discussed with fellow engineers in the industry. The first two days proved to be very good, so how was the third day? We'll look at that next time. Meanwhile, I welcome your thoughts on a method to perform more graceful clipping. Can it be done?

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9 comments on “An Applications Engineer’s Perspective of IMS2013 – Day 2

  1. goafrit2
    June 19, 2013

    I like this piece but was curious what the difference would have been on IMS2013 from the perspective of a design, tester or otherwise. Does the job area shape how people see these shows and conferences? I am curious as that can help determine who goes to which show?

  2. jonharris0
    June 19, 2013

    Thanks for the comments.  I would imagine that there is some difference of perspective depending on the role of the attending engineer.  I was there to support products for my company and learn from our customers.  There are so many types of engineers that are usually at the show it would be hard to guess the perspective of each.  I think shows like IMS offer a great benefit to many roles of engineers from design to test to apps in companies of all sizes.  It really depends on what you are looking for at a show to determine whether or not to go.  I think for someone working with frequencies from a few hundred MHz up to 10s of GHz this show has it all covered.  There is something for every type of engineer to benefit from.

  3. RedDerek
    June 19, 2013

    When I wore the applications engineering hat, I found trade shows were very useful. It allowed me to interface with the customers, find out what is needed and by whom, observe new products to market to, and many other opportunities abound. However, it does take the app engineer that is always looking at new problems to solve and has some marketing skills. A typical engineer from the cubicle may not be worth the trade show arena unless it is a local show.

  4. bjcoppa
    June 19, 2013

    Conferences are a great way to get a quick glimpse of the overall status of an industry. I have had the opportunity to attend many over the last couple years. It's amazing how disconnected tech professionals in the field can be who never attend any or do not keep up with trade journals on industry trends. Doesn't take long to fall off the cliff and lose sight of your competitors and innovation.

  5. Brad Albing
    June 24, 2013

    Jonathan – that helps. Also, these shows generally have good overview info on their websites along with info on previous years' presentations and the upcoming presentations. So that should help.

  6. Brad Albing
    June 24, 2013

    @RedDerek – I'd agree with that – same scenario for me when I worked as an apps engineer. The shows really help open your eyes to what's goung on with the customers – lots of info, thrown at you pretty quickly. And you do need to be a bit of a salesperson/marketing guy to handle it.

  7. goafrit2
    July 7, 2013

    >>  I was there to support products for my company and learn from our customers. … There is something for every type of engineer to benefit from.

    No problem. It is very evident that you enjoyed the problem.

  8. goafrit2
    July 7, 2013

    >> A typical engineer from the cubicle may not be worth the trade show arena unless it is a local show.

    Yes, that has been the issue. As a designer, I attend only ISSCC which focuses on circuits and systems. Of course my colleagues in the application engineering area does the marketing and sales and must attend these shows to showcase the products and services.

  9. goafrit2
    July 7, 2013

    >> Doesn't take long to fall off the cliff and lose sight of your competitors and innovation.

    Yes, you can get a lot of insights on the industry in these programs. However, notice that most of the players may not be showing the best they have got. In my company, they rarely allow you to talk about the real deal. So, you can still attend conferences without getting the real pulse of the industry.

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