Category Archives: education

Intuitive CMOS transistor modeling

On Oct. 6, 2015, I gave a guest lecture in the lecture series “Structured Electronic Design” (EE4C09) on Intuitive CMOS Transistor Modeling. In there I explain the 5 regions of operation of an MOS transistor (both in weak inversion and in strong inversion, both in triode and saturation, and off), based on the EKV model. For those of you that might still be struggling with understanding how the CMOS transistor works and how it can be employed in first time right, first time best analog and mixed signal circuit design, this lecture is for you.
See the complete lecture, which also treats double loop negative feedback amplifiers, herehttps://collegerama.tudelft.nl/Mediasite/Play/d2fc417f2e644a64b4463e34322f86a31d?catalog=528e5b24-a2fc-4def-870e-65bd84b28a8c

Do you really listen or hear?

Learning in the true sense of the word is possible only in that state of attention, in which there is no outer or inner compulsion. Right thinking can come about only when the mind is not enslaved by tradition and memory.”

–  Jiddu Krishnamurti

Considering all the senses we possess, the post could have been named “Do we see or look?” or perhaps  “Do we speak or talk?”. But among the three, I would like to focus more on the capability to hear and listen, which also holds relevance to the research conducted at the bioelectronics group. To provide a sense of appreciation, simply look at how elegantly the brain processes the sounds we hear, with clear distinctions in frequency and amplitude making innumerable nervous connections, to generate a unique experience. For instance, when you hear the far away church bell ringing in a crowded marketplace, it fills you with joy and hope. If you care about the quality of the sound and prefer using high end headphones, you would know the joy of heavy bass sound and clear vocals that you savor while listening to music!

With tremendous advancements in microelectronics, thousands of individuals with varying degrees of disabilities are now able to hear better with the support of hearing aids, where the size of the aid is diminishing rapidly, while maximizing comfort. As an example, the cochlear implants (CI) are being used for the restoration of the hearing ability and is on the road to absolute bliss in audition. As exciting and extreme the research continues to be, I would like to draw your attention to the significance of listening, going beyond hearing, and the differences lying therein.

Although we have managed to bring about considerable improvement in the hearing abilities of the people through scientific progress, have the fully abled beings actually made complete use of the capabilities in a way that would enhance their personalities and their understanding? Do we truly listen?

Difference between hearing and listening

When we hear someone speak, we produce our own formulations and thoughts, we are either accepting or rejecting his/her idea, as the speaker speaks. We stand to compare his words with what we think based on the background, knowledge base and the experience we possess. This very fact is the denial of listening. While hearing is the ability to perceive sound by detection of the changes in pressure in the surrounding medium, which is involuntary, listening is an act you choose to do voluntarily, a decision you take consciously.

In Jiddu Krishnamurti’s words, in listening there is no comparison, neither is there acceptance nor rejection. The quality of listening is your attention. When you listen, every part of your body is in rapt attention to what is being spoken, intensely, where there is no judgement. There is no confusion but absolute clarity. You are neither influenced by the person’s appearance, nor intimidated by his presence. When you do that, you listen to the subject of discussion wholly. You are then in a position to discriminate right from wrong. There is a strong inner urge to understand the speech fundamentally, and not superficially be steered by the speaker and/or being ignorant. You are then very observant of the changes that are taking place within you, subtle nevertheless. A detailed discussion is available here for the interested reader.

Krishnamurti speaks in depth about the state of the mind while listening. A calm mind can perceive and listen with great clarity. Also, such a mind can have positive influence on the environment, the essence of which is well captured in one of Krishnamurti’s commentaries about “The noisy child and the silent mind” and is available here. As another example, in the movie Karate Kid (2010), Kung Fu master Mr. Han (Jackie Chan) takes Dre Parker (Jaden Smith) to the Dragon well on top of the mountain. Mr.Han explains the state of mind of the lady (who controlled the snake) which was calm and still just like the water in the well where Dre looks at his own reflection. The scene is available here (Watch from 1:13:00 to 1:17:10).

To give an analogy in the circuits and signal processing domain, when we need to acquire a signal, while ensuring quality and reproducibility in the digital domain for a given application, both internal and external noise have to either be minimized or rejected. In the same way, only a quiet mind can perceive and experience what is beyond hearing and also understanding. And often, the quality of listening goes with the choice of words one uses in his/her speech. As you begin to listen better, your thoughts become refined and so do your words. You then begin to filter all that is noise and only recover your signal of interest.

On another note, it is important to use one’s own discretion in placing the attention. Considering the information society we live in, there is a vast wealth of information on every subject. What we choose to learn is an individual choice. A wealth of information creates a dearth of attention, derived from the concept of attention economy, first studied extensively by Herbert Simon.

While we aim to bring about improvement in the the lives of people with hearing disabilities, we also need to give a thought towards how effectively we use our perfectly functioning abilities. How we take things for granted! If we didn’t, the experience would be more enriching, so much more happier and so much more wholesome!

As Helen Keller said,
So much has been given to me I have not time to ponder over that which has been denied.
This should not only motivate oneself to look within, reflecting on the challenges and converting every disadvantage to an advantage, but also placing a check on whether we use our inherent faculties to the total extent. It is just like owning a Lamborghini Aventador but being limited to use it as a Dacia Sandero on legal roads or employing an ARM micro-controller to make an LED blink!

                                                   ***
About Jiddu Krishnamurti

jk  Born (11 May 1895 ) in Mandanpalle, Andhra Pradesh, India, Jiddu Krishnamurti, an Indian philosopher, is globally regarded as one of the greatest educators and thinkers. He had a deep sense of appreciation and respect for nature, as it appears in his notes. When he spoke, he did so with his own insight and vision, which had a certain directness and freshness.

About Hellen Keller

hk Born (27th June 1880) in Tuscumbia, Alabama, U.S., Hellen overcame the adversity of being deaf and blind to become one of the 20th century’s leading humanitarians as quoted here.

Suggested reading and references

  • Commentaries on Living, Jiddu Krishnamurti
  • Education and the significance of life, Jiddu Krishnamurti
  • Story of my life, Hellen Keller

 

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Een betere toekomst begint vandaag

maslov_eeVoor verwelkoming van de aankomende 1e-jaars van de opleiding Electrical Engineering aan de TU Delft maakte ik tijdens het “Electro Ontvangst Weekend” (EOW) een presentatie. Deze presentatie vind je hier: http://elca.et.tudelft.nl/~wout/tmp/eow_2015_serdijn.pdf.

Neural stimulation: design of efficient and safe neural stimulators

Article by Marijn van Dongen on efficient and safe neurostimulation

Article by Marijn van Dongen, honorary aluminus of the Bioelectronics Group, in Maxwell 18.3, the quarterly magazine of the Electrotechnische Vereeniging, on the work he did for his PhD studies on power efficient and safe neurostimulation.

Read the entire article here: http://elca.et.tudelft.nl/~wout/tmp/neurostimulation_maxwell_18.3_vandongen.pdf

Lecture on Electroceuticals: getting better with electricity

Lecture on Electroceuticals: getting better with electricity

Lecture on Electroceuticals: getting better with electricity

On May 6, 2015, Collegerama of TU Delft made video recordings of the lecture I gave on Electroceuticals.

Electroceuticals are the electronic counterparts of pharmaceuticals and are miniature electronic devices that interact with the body in an electrical fashion.

In this talk I discuss: neurostimulation and the need to make neurostimulators smaller, more power efficient and more intelligent; optogenetic neuromodulation and the need to make this new neuromodulation modality operate in a closed-loop fashion; neurosensing devices to make neurostimulators intelligent and thereby adjust themselves to the therapeutical needs of the patient; autonomous wireless sensor nodes that can measure temperature or the electrocardiogram without the need for a battery; an outlook into the future of electroceuticals with the promise to treat a larger variety of neurological and brain disorders better.

Click here to start watching the video and slides:

https://collegerama.tudelft.nl/Mediasite/Play/cc7888beb88349c1a60c1414476b577a1d?catalog=528e5b24-a2fc-4def-870e-65bd84b28a8c

REMINDER: ISCAS 2015 Advance Registration Deadline (April 30th) Approaching Quickly

REMINDER: ISCAS 2015 Advance Registration Deadline Notice & Call for Participation

2015 IEEE International Symposium on Circuits and Systems (ISCAS) Lisbon, Portugal
24-27 May 2015

http://www.iscas2015.org/

ISCAS 2015 HIGHLIGHTS:
– Keynote by Behzad Razavi: “The Future of Radios”
– Keynote by Ronald Dekker: “From Chips for the Living to Living Chips”
– Keynote by Luís Gomes: “Changing the Economics of Space: Small Spacecraft and COTS Electronics”
– John Choma Commemorative Session on Reconfigurable and Adaptive Analog, Mixed-Signal, and Radio-Frequency Integrated Circuits, with contributions from Yannis Tsividis, Franco Maloberti, Edgar Sanchez-Sinencio, Hossein Hashemi and Randy Geiger.
– John Choma Commemorative Session on Ultra-Low-Power Integrated Circuits and Systems for Biomedical Implants, with contribution from Mohamad Sawan, Ralph Etienne-Cummings, Wouter Serdijn, Herming Chiueh and Roman Genov.
– Conference Leadership Workshop

HOTEL RESERVATIONS:
Rooms at different hotels in Lisbon have been booked for the convenience of the participants and are to be assigned on a first-come first-served basis. Please visit the conference web site for additional information.

http://www.iscas2015.org/travel/hotels/

Advance Registration Deadline: April 30th

GENERAL CHAIRS’ MESSAGE

Queridos amigos,

On behalf of the Organizing Committee, we are pleased and honored to invite and welcome you to Lisbon and to the 2015 IEEE International Symposium on Circuits and Systems (ISCAS 2015). The conference theme, “Enabling Technologies for Societal Challenges”, in line with the 2020 European Research and Innovation Roadmap and the Grand Engineering Challenges, suits extremely well our community’s inter-disciplinary and cross-disciplinary research activities.

ISCAS is the main event of the IEEE Circuits and Systems Society and the world’s premier networking forum for leading researchers in the highly active fields of theory, design and implementation of circuits and systems. The Technical Program Co-Chairs for this year edition, João Goes and Philipp Häfliger, have assembled an outstanding program with three full days of lectures and poster sessions covering 16 tracks. The most outstanding contributions to these tracks will be considered for the Best Student Paper Award contest and the Best Live Demo Award contest. The winners of both awards will be selected and announced during the conference.

ISCAS 2015 also offers high-quality and leading–edge tutorials and special sessions from worldwide experts, either in specific and in multidisciplinary areas, suited for those looking for a birds-eye view on a new research area or to improve their areas of expertise.

A set of world-class keynote speeches will be presented.

Apart from the scientific contributions, ISCAS 2015 will offer a forum that promotes the interaction between industry, start-ups, PhD students, academia and research funding agencies. This interaction will have place through industry presence, debates and talks.

ISCAS 2015 maintains the Women in CAS (WiCAS) activity as well as the Young Professionals Program (YPP) activity and will also host a “Conference Leadership Workshop”, a Special “John Choma Commemorative” Session with 10 distinguished invited speakers and other events, further enriching the technical program.

As for the social program we will try to match the quality of the technical program and of the tutorial offerings. On Tuesday, the Award Ceremony will be held in an opera house auditorium followed by the Gala Dinner in the Convento do Beato, a magnificent former monastery that dates back to the 15th century.

ISCAS 2015 will assist in sharing and disseminating your specific and inter- and cross-disciplinary technical achievements and will bring together diverse participants, histories and cultures. We look forward to your active participation in this magnificent event!

Um abraço,
Jorge Fernandes and Wouter Serdijn

Future hardware improvements in implantable hearing devices

Damaged situation of the middle and inner ear; hair cells are damaged or non-existent, nerve cells are not fully developed or do not reach the cochlea [3].

Damaged situation of the middle and inner ear; hair cells are damaged or non-existent, nerve cells are not fully developed or do not reach the cochlea [3].

In this essay, by Ide Swager, MSc student in bioelectronics, an overview of current and future developments in implantable hearing devices is presented. It has been written as part of the course Introduction to Microelectronics for the M.Sc. track Microelectronics of the faculty Electrical Engineering, Mathematics and Computer Science of Delft University of Technology. A brief version of the auditory anatomy is included to clarify the causes of deafness. After elaborating on the current devices available and the basic working principle, future trends are explored. These include Neural Response Telemetry (NRT), combined Acoustic and Electric Stimulation (EAS) and binaural devices.

Read the full essay here: http://elca.et.tudelft.nl/~wout/tmp/iswager_essay.pdf

IEEE CASS Summer School on Wearable and Implantable Medical Devices; intro of my talk on low-power low-voltage circuit design on YouTube

YouTube Preview Image

Published on Jul 10, 2013

Una pequeña descripción de su investigación, en circuitos de bajo consumo y miniaturización de los mismos. Su descripción aqui http://cass-school.uniandes.edu.co/lecturers.html.

A new name, but Biomedical Electronic remains

Biomedical Electronics Lab

Dear Reader,

The Biomedical Electronics Group underwent a small name change. From now onwards, the group is called “The Biomedical Electronics Laboratory”.

Its mission is “to provide the technology for the successful monitoring, diagnosis and treatment of cortical, neural, cardiac and muscular disorders by means of electroceuticals.”

To this end it conducts research on, provides education in and helps creating new businesses in neuroprosthetics, biosignal conditioning / detection, transcutaneous wireless communication, power management, energy harvesting and bioinspired circuits and systems.

New Book: EMI-Resilient Amplifier Circuits

EMI-Resilient Amplifier Circuits

EMI-Resilient Amplifier Circuits

van der Horst, Marcel J., Serdijn, Wouter A., Linnenbank, André C.

2013, XIV, 300 p. 75 illus., 1 illus. in color.

ABOUT THIS BOOK
Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers
Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements
Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detrimental effects on noise and stability
This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers. The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER). This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in application specific amplifiers in order to meet the SER requirements.

· Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers;

· Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements;

· Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detrimental effects on noise and stability.

Content Level » Research

Keywords » Analog Integrated Circuit Design – EMI – EMI-resilient – Electromagnetic Compatibility – Electromagnetic Compatibility Engineering – Electromagnetic Interference – Electromagnetic Interference-resilient – Negative-feedback Amplifier Circuits – Signal-to-Error Ratio

Related subjects » Applied & Technical Physics – Circuits & Systems – Electronics & Electrical Engineering

TABLE OF CONTENTS
Introduction.- Decreasing the disturbance coupled to amplifiers.- Modelling of active devices.- The Cascode and Differential amplifier stages.- Design of EMI-resilient single-stage amplifiers.- Design of EMI-resilient dual-stage amplifiers.- Realizations.- Conclusions and recommendations.