Category Archives: Conferences & Seminars

NoMe TDC 2013


If you’re interested in Time-to-Digital Converters (TDC), and have been looking for a more dedicated event, you may want to check out the 2013 IEEE Nordic Mediterranean Workshop on Time to Digital Converters held in
Perugia, Italy, 3 October 2013.

You may still remember what I think about having data-converter conferences in Italy – it’s a fantastic idea. The food, the beautiful landscape, historic buildings and nice weather made me fall head over heels in love with the country. So check the conference site out to see if it’s something for you.

These conference snacks were served in Orvieto, but I’m sure that no one is going to starve in Perugia either … 😉

Back from ECCTD 2011

After the crystal-clear scientific presentations at ECCTD, I'm now back in the mist again.

So, I’m back from ECCTD 2011 since late Wednesday, and up here at the southern edge of the northern half of Sweden, the mornings are misty and the leaves are turning yellow. Visiting Linköping was every bit as pleasant as I had expected. The conference was held at Linköping Konsert & Kongress, which is beautifully located at the center of the city, right next to the Linköping Cathedral.

The conference

The conference was excellently organized by the Electronics Systems division at Linköping University and the conference committee. I was particularly impressed with the student helpers. Not only were they helpful, kind and attentive, but quite a few of them also turned out to be passionate about data-converter research and development [one of the healthier states of the human mind, BTW 😉 ] and we had several interesting conversations on the topic. I couldn’t possibly have felt more welcome.

Professor Borivoje Nikolić speaks about managing variability.

After we all had been welcomed by the conference general chair, prof. Lars Wanhammar, Linköping University, the conference started with a plenary presentation “Managing Variability for Ultimate Energy Efficiency” given by prof. Borivoje Nikolić from UC Berkeley, USA. The conference then split up into various sessions which are described in detail in the program. ECCTD is a rather broad conference, but there were at least three dedicated data-converter sessions: “Sigma-Delta Modulators“, “Data Converters“, and “Pipelined ADCs“. I had the honor of chairing “Pipelined ADCs“, and I presented my own contribution “Area Efficiency of ADC Architectures” in the “Data Converters” session. I might come back to the content of that paper in another post, but in short (for those of you that were not there), it surveys the chip area vs. performance in speed and resolution for just about every ADC implementation reported in the scientific literature all the way since 1974 – approximately 1500 papers. A normalized area measure

A_{Q} = \dfrac{A}{{2}^{ENOB}}

was proposed based on the observed correlation between absolute chip area (A) and effective resolution (ENOB). State-of-the-art AQ – a.k.a. “Area per effective quantization step” – was seen to be independent not only of ENOB, but also of sampling rate over a broad range of sampling rates and resolutions, respectively. It is also approximately independent of CMOS process node. Chip area per effective quantization step was then compared for individual architectures, and design guidelines derived for area-optimal ADC architecture selection at any given speed and resolution specification. It was seen that there are large differences in the peak area efficiency achieved with different ADC architectures. There is for example a factor of 3 difference between SAR and pipeline, and a factor of 10 between pipeline and flash. Such big area differences can translate to a lot of money if you’re developing high-volume ADCs. So make sure you get hold of this paper as soon as it comes up on IEEE Xplore.

The blogger as session chair. Photo: Mark Vesterbacka

Professor Mark Vesterbacka, Linköping University had to push the electronics in his mobile phone to the maximum in order to document my chairing efforts in spite of the low light. Thanks for sending the picture.

CWCP winner

I could notice a slight peak in blog visitors yesterday. I assume that many of you wanted to know who won the Connect-with-Converter Passion (CWCP) prize, and I apologize for not being as fast as Dr. J Jacob Wikner who was blogging live from ECCTD and managed to fire away several conference-related post on Mixed-Signal Electronics while ECCTD was still developing. One of them correctly revealing that we had a CWCP winner already after the first day. And the winner is:

CWCP-winner Kiran Kariyannawar

Kiran Kariyannawar from Ericsson AB, who showed the enthusiasm and dedication necessary to win the CWCP prize for ECCTD. Congratulations Kiran! Kiran was there together with other Ericsson colleagues to demonstrate The Connected Tree and how to transmit audio and video signals through the human body. Quite far out compared to most demonstrations I’ve seen at scientific conferences. Very fun (at lest from a tech nerd’s perspective), and I’m sure they will figure out a lot of applications for it eventually, although for now they didn’t seem quite sure what to do with it. At least not with the connected tree. I played a bit with the human-body transmission (by becoming the channel), and I think it could be great for DJ-ing. I was just about to get it to rock big time when I started to realize the other delegates need for less noise and gave it up. If only I had a few more minutes to work out that groove …

The next big thing in DJ-ing? Just intermittently add a human body connected between those metal plates – preferably in a rhythmic pattern – and you're all set.

Other impressions

The conference dinner was held at the Air Force Museum – a place I’m likely to return to again to have more time to look at everything. Most likely with the rest of the family. A few photos below will give you some idea of the location. Finding unorthodox locations that can make the conference dinner extra memorable is probably a real challenge to most organizers. Unless they start taking us to outer space and back, I believe that the abundant food stations in combination with the breathtaking beauty of sea life shown at Monterey Bay Aquarium (ISCAS 1998) will remain my personal favorite for the rest of my life, but with ECCTD 2011 now being among the top two. Excellent work!

A classic Swedish beauty.

Chopper techniques. Large implementation.

A peaceful dinner ...

A missile of some kind, with a sign in Swedish saying "DO NOT PUSH HERE". Now, how irresistible is that on a scale to ten? Photo: M. Reza Sadeghifar

Having been to a few conferences, you start to recognize some faces that keep coming back. I had the pleasure of meeting delegates I’ve recently met. Some at NORCHIP, some at ICECS, and others at IWADC. It was great seeing you all. That is the real value of going to conferences.


ECCTD 2011 face-recognition. Note that we observed a severe Linköping bias here that might be compensated for in "future work".

Connect with Converter Passion at ECCTD 2011

Hi all, and sorry about the low posting frequency during the summer. Now I’m here again, and this time to announce the Connect with Converter Passion (CWCP) competition for ECCTD 2011 next week. As always, I want to take the opportunity to connect with blog readers, and to give you some visibility.

Same face – new conference

To win the prize (which is the glory of winning + some visibility on this blog), all you need to do is to be the first one to locate me during the conference and claim the prize. Couldn’t be much simpler. Since the Linköping University group that is organizing the conference has a strong history of winning the CWCP prize, I will discriminate slightly against them this time (sorry guys) – but just slightly – to give the rest of you a fair chance. Affiliates of Linköping University will not be allowed to claim the prize until the second day of the conference (Tuesday). But don’t forget to try, because it may still be up for grabs by then.

If you haven’t located me before that, Tuesday is also a safe day to find me, as I’m presenting my ECCTD contribution “Area Efficiency of ADC Architectures” in session T21, Data Converters (starting 15:50). Last chance is around the W33 session, Pipelined ADCs, which I’ll be chairing on Wednesday afternoon.

Looking forward to seeing you in Linköping next week.

Going to Linköping … Yes, Yes, Yes!!

Curves like these can be really useful if you're going for small chip area. Those who attend ECCTD 2011 will get the full picture and learn what's on the X and Y axes.

You’d be forgiven to think that, with all the praise I recently gave to Italy and the IWADC conference, there’s no room in my heart for any other conference or location. But going to the European Conference on Circuit Theory and Design in Linköping, Sweden will be very special. The location isn’t nearly as exotic to me as Italy – quite the opposite in fact. I used to study in Linköping, and I was also a PhD student at the very department that is hosting the conference. What is special with Linköping is that it’s the city I used to call home for about 15 years of my life – 15 good years filled with memorable moments, good friends and talented engineers and scientists. It’s a nice Swedish town, and I highly recommend you to go there. ECCTD 2011 offers the perfect excuse.

If, like me, you’re also interested in what’s actually presented at the conference, it too is an excellent reason to go there. I guess there will be a conference program up on the conference site sooner or later. Until then I can only tell you about my contribution “Area Efficiency of ADC Architectures”, which I was very glad to get accepted. No extra points for guessing the general topic of the paper, and I’m not going to spoil the fun by telling you everything about it. Suffice to say that it’s another huge survey of scientific A/D-converter achievements. This time we’ll take a first look at the area-efficiency of various ADC architectures at different speed/resolution specifications. It exemplifies a small fraction of the EDO methodology used by ADMS Design AB, and gives you some overall guidelines to get you started with area-optimized ADC design.

So, if you design ADCs for high volume production and a low manufacturing cost is important … don’t miss this paper.

Back from IWADC 2011

Views from Orvieto (click to enlarge)

I’m completely in love with Italy now. It was my first time there, and I was impressed by just about every aspect of the visit – the beautiful landscape, the fascinating history embodied in ancient buildings, and of course by the people. Perhaps it was accentuated by me going through the “vanilla phase” with Italy, but it did seem very easy to get a kind smile from just about any Italian I met throughout the entire trip.

A fraction of the big happy family of IWADC delegates

Attending IWADC 2011 was every bit as pleasant: The conference itself ran like clockwork, the medieval city of Orvieto was a decidedly pretty conference location, and the relatively small size of the conference contributed to the relaxed and friendly character of the event. Almost like a family event – a big happy Italian family, I could imagine :-). The feeling of being welcome and surrounded by “family” was very much accentuated by the hospitality shown by the conference general chair, professor Paolo Carbone (University of Perugia), members of the organizing committee, and other delegates. During the conference dinner when we were also treated with one tasty Italian dish after another, I remember uttering something like “all conferences should be in Italy”. That’s how good it felt to be there.

Who doesn’t love Italian food? I was late to some sessions because I tried to eat all the Salatini before they cleared the tables …

CWCP winner

A winner: Yu Lin

Now being a solid tradition, each conference I attend needs to have an opportunity to connect with Converter Passion. To motivate conference delegates to not be shy we came up with the Connect with Converter Passion (CWCP) prize. The rules are simple: First blog reader to find me at the conference and claim the prize is the winner, and for IWADC 2011 the winner is Yu Lin, a PhD student at Technical University of Eindhoven who was also presenting the paper “An Input Signal Statistics Aware Design Approach and Examples for Analog-to-Digital Converters for communication systems” at the conference [co-authors: Kostas Doris (NXP), Hans Hegt and Arthur van Roermund (TU Eindhoven)]. It was a pleasure to meet such a motivated blog reader. Yu aimed for victory and did not hesitate to claim the prize already at the informal pre-conference reception at restaurant Maurizio. Definitely the right spirit and a worthy winner indeed. Congratulations! Normally, the competition is only for the glory, but this time a small surprise memento was added in the form of a handmade key ring in black leather produced by “Boothill Bob” from Boothill Bob Holsters.

The conference

IWADC covers ADC modeling, testing and data converter analysis and design. Because it is an IMEKO conference, various aspects of measurement becomes a natural thread in many contributions, although the scope is rather wide. It includes calibration of ADCs and error correction of the ADC output, such as presented in the papers “Digital background calibration of subsampling time-interleaved ADCs” by Centurelli from Università di Roma la Sapienza, and “A Linearization Strategy for Undersampling Analog-to-Digital Converters” by Vallant from Cassidian Electronics. Time-to-Digital Converters (TDC) seems to be a growing field, and a fair number of papers addressed various aspects of TDCs, for example “Modeling Noise Effects in Time-to-Digital Converters” by Napolitano, University of Perugia, and “Time-to-Digital Converter (TDC) with Sub-ps-Level Resolution using Current DAC and Digitally Controllable Load Capacitor ” by Alahdab from University of Oulu. There were classic ADC implementation papers such as “A 6-bit 3GS/s Flash ADC in Bipolar 0.25 um for the radiotelescope SKA” by Da Silva from Station de Radioastronomie de Nançay, and I personally found it interesting to hear about ADC implementations in emerging materials, as in “ADC Design in Organic Thin-Film Electronics Technology on Plastic Foil” by Marien of K. U. Leuven.

Scientific discussions

Of my own contributions, the first (An empirical approach to finding energy efficient ADC architectures) was about using the measured performance of chips made by others to better optimize your own design, and the second (Using Figures-of-Merit to Evaluate Measured A/D-Converter Performance) treated how to assess the quality of figures-of-merit often used to make comparisons of measured performance.

IWADC face recognition

There were many more papers presented at the conference, but I don’t intend to walk you through the entire program. Note also that I have mostly mentioned the first authors above although most papers have one or more co-authors. Please add comments below and tell us about any papers, co-authors or delegates that you wish to mention. Or just say hi, and let everybody know you were there too. Share the name of your contribution, and your impressions from the conference with us.

Yes, I was there. Here together with publication chair, Dr. Antonio Moschitta (left) and general chair, professor Paolo Carbone (right).

To round it off, I’ve made a pie chart of the distribution of delegates between countries, based on statistics provided by professor Carbone. As could be expected, the Italian representation was strong. The rest of the countries are quite evenly represented. As you can see, delegates came from both USA and China, although the vast majority were from European countries.

Distribution of IWADC 2011 delegates by country

Please post your comments below if there is anything you’d like to add about the conference.