Tag Archives: CWCP

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.

Peace! 

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

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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.

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.

Connect with Converter Passion at IWADC 2011



Anyone planning to attend IWADC 2011 – the international workshop on ADC and data converters – in Italy the coming week?  Then make sure to connect, and you may win the Connect-with-Converter Passion prize for IWADC 2011. The reward is to have yourself mentioned here on the blog (see winners from last years NORCHIP and ICECS here and here), and the only thing you need to do to win is to be the first attendee to locate me during the conference and claim the prize. Besides announcing and introducing the winner of the CWCP,  I also plan to highlight a few interesting papers, pick up the conference “vibes” and share it in my reporting from the conference. I’ll be interested to talk to all of you, so even if you didn’t win the CWCP race I will be very happy to hear what you have to say about the conference, tech blogs, or the data converter field in general. What are your views on ADC FOM, the data converter market and scientific trends for the next decade, and more …

Look for this face

If you haven’t found me before, a safe bet is around the High-efficiency Data Converters session (Thursday 14:15–15:45) where I will present my first contribution An empirical approach to finding energy efficient ADC architectures , or at the Poster Session II for which I am chair on Friday, and where I will also present my second contribution Using Figures-of-Merit to Evaluate Measured A/D-Converter Performance. For more details, see the “Going to Italy, Yes, Yes, Yes!” post, and the conference program.

Back from ICECS 2010


The blogger (left) enjoying his lunch dessert together with Fahad Qureshi (middle), and the ICECS 2010 winner of the “connect-with-Converter-Passion” prize, Syed Ahmed Aamir (right). Photo: Currently unknown (email me).

Well, just being able to write “back from ICECS 2010” is a major victory, as the hundreds of scientists trying to come home from Athens may testify. Transportation strikes in Greece combined with unusual amounts of snow and bad weather clogging up several European airports at once, made the trip back home slightly more adventurous than usual. I managed to slip through most of the tight net created by these circumstances, and have realized from watching the news that the few bumps I encountered still left me as one of the lucky guys.

A winner!

Speaking of lucky guys: The clear winner of the “Connect-with-Converter Passion” race this time was Syed Ahmed Aamir, student at Linköping University, Sweden. Although nothing was set in stone, he showed all the signs of a winner already in this comment. Something that may have scared off most of the competition. In order to break the complete Linköping dominance in this race, I’m planning to not consider the local organizers (Linköping University) eligible for the prize if I go to ECCTD 2011. Either way, Aamir came to Athens to present his own paper “A 1.2-V Pseudo-Differential OTA with Common-Mode Feedforward in 65-nm CMOS”, and a paper by Armin Jalili Sebardan et. al – also from Linköping – entitled “Calibration of High-Resolution Flash ADCs Based on Histogram Test Methods”. Their colleague, Fahad Qureshi, presented the paper “Alternatives For Low-Complexity Complex Rotators”.

More ICECS delegates

A nasty cold forced me to rest more than planned, and that hampered my networking activities to some degree. I did however manage to see Dr. Skyler Weaver from Oregon State University presenting his paper “PDF Folding for Stochastic Flash ADCs”, and the poster “Asynchronous CLS for Zero Crossing Based Circuits” by OSU colleagues Hariprasath Venkatram, et al. Unfortunately for Dr. Weaver, we ended up at the same banquet dinner table in the beautiful Vorres Museum. Rather than enjoying his meal with a socially competent table-mate chatting about music, sports and the weather, his brain was contaminated all night long with my various views on ADC design, the correct use of ADC figures-of-merit and the likes. You can imagine the trauma … 😉

Skyler is obviously a man with a big heart and lots of patience.

View from the Chair: The five authors preparing for the session.

I also have to commend all five presenters in session W1L-B (Analog-to-Digital Converters II), for which I was chair: You all showed up with your presentations in good order, and you were very disciplined staying within your time-slots. Your reward will be a slightly raised web presence by having your work highlighted here. The complete session was:

  1. Column Parallel Single-Slope ADC with Time to Digital Converter for CMOS Imager”, presented by Muung Shin from Hokkaido University, Japan.
  2. A Digital Processor for Full Calibration of Pipelined ADCs”, presented by Dr. Javad Frounchi from University of Tabriz, Iran.
  3. Comparison of DEM and BEET Linearization Techniques for Flash Analog-to-Digital Converters Using a SFDR Metric”, presented by Christopher D. McGuinness from University of Dayton Research Institute.
  4. An Ultra Low Power 9-bit 1MS/s Pipelined SAR ADC for Bio-medical Applications”, presented by Guohe Yin from University of Macau, China.
  5. Mismatch Aware Power and Area Optimization of Successive-Approximation ADCs”, presented by Jia Mao from Royal Institute of Technology, Stockholm, Sweden.

As previously shown, there were around 27 ADC-related papers altogether, and I’m not going to list them all here. You will soon find the entire proceedings on IEEE Xplore, and I don’t want to spoil all the fun by telling everything about the conference. As always, the comment field below is open for you to add your own views and comments. If you want to highlight any other paper, participant or author, just go ahead and do it. By all means, promote your own work too! Don’t be shy …

Enjoy the output of your own research field: Nifty proceedings and gadgets.

ICECS 2010 Proceedings and some final thoughts

I know it’s probably getting commonplace by now, but I still can’t help but liking the design and implementation of conference proceedings also this time: A pen, laser pointer and USB memory all in one. Very practical indeed, and I’m still dwelling on the fact that with proceedings like these we’re reaping the benefits of our own research in microelectronics.

Some of you have been mentioned above, but I met many other delegates that in one way or another made ICECS 2010 a memorable event. Thank you all for novel ideas, a kind smile, a good chat during coffee breaks, and for nice company at the tables. You know who you are. Makes yourselves known to the world by posting a greeting below.

Also, if you have anything you want to ask about my paper “A Survey of A/D-Converter Performance Evolution”, or want to add anything to what I’ve written above, feel free to do so in your comments.

Finally, I haven’t decided yet what conference(s) to go to next – in case you’re wondering about the next opportunity to win the connect-with-CP prize. Both ECCTD 2011 and the 2011 IMEKO IWADC & IEEE ADC Forum have showed up on my radar looking good. Why not check them out?

BTW: