Ángel Rodríguez-Vázquez - Selected Publications#

Selected publications of Prof. Rodriguez-Vázquez are clustered into four groups, namely:#

• Smart imagers and vision chips
  
• Mixed-signal nonlinear signal processing and circuits
  
• Analog-to-Digital Conversion with emphasis on oversampled data converters
  
• Bio-medical and bio-inspired circuits and systems
  

SMART IMAGERS AND VISION CHIPS

His contributions are rooted in the papers:

[1] A. Rodríguez-Vázquez et al., “Nonlinear Switched-Capacitor Neural Networks for Optimization Problems”. IEEE Trans. on Circuits and Systems, Vol. 37, pp. 384-398, 1990.

[2] A. Rodríguez-Vázquez et al., “Current Mode Techniques for the Implementation of Continuous and Discrete-Time Cellular Neural Networks”. IEEE Trans. on Circuits and Systems, Vol. 40, pp. 132-146, 1993.

[3] T. Roska and A. Rodríguez-Vázquez, “Towards Visual Microprocessors”. Proceedings of the IEEE, Vol. 90, pp. 1244-1257, 2002.

Pub [1] set a milestone in the implementation of analog parallel processing using mixed-signal circuits. Methods and circuits in this paper were basics for further activities on vision chips with analog pre-processing. Pub [2] reported dedicated circuits to implement early vision processing kernels; it received the IEEE Guillemin-Cauer CASS award. Pub [3] defined the basis for embedding parallel digital computer concepts (distributed local memory, software programming, etc.) in mixed-signal chip arrays. This paper was completed with a Wiley book entitled Towards the Analogic Visual Microprocessor - ISBN 0-471-95606-6.

These seminal publications prompted papers in IEEE JSSC, IEEE Trans-on-Multimedia, IEEE Trans-Neural-Networks, etc., contributing subsystems, chips and applications. The epitome was:

[4] A. Rodríguez-Vázquez et al., "ACE16k: The Third Generation of Mixed-Signal SIMD-CNN ACE Chips Toward VSoCs". IEEE IEEE Trans. on Circuits and Systems -I, Vol. 51, pp. 851-863, 2004.

AnaFocus started on the basis of this publication [4]]. This company produced the first truly programmable industrial Vision-System-on-Chip, called Eye-RIS reported in:

[5] A. Rodríguez-Vázquez et al., "A CMOS Vision System On-Chip with Multi-Core, Cellular Sensory-Processing Front-End". ISBN 978-1-4419-1011-0, Springer 2010.

Back to academia from 2009 Prof. Rodriguez-Vázquez has co-authored some 40 papers addressing long-term challenges related to CMOS imagers and vision chips with emphasis : i) Low light detection and high dynamic range acquisition; ii) Single photon detection and 3D smart imaging; iii) 3D integration architectures for vision chips. These contributions have been reported mostly in IEEE Sensors J., IEEE Journal of Solid-State Circuits, IEEE Trans. on Circuits and Systems and IEEE Journal of Emerging Technologies on Circuits and Systems and have deserved 2 best paper awards from IEEE ISCAS and 1 best paper award from SPIE/IST Electronic Imaging.

MIXED-SIGNAL NONLINEAR SIGNAL PROCESSING AND CIRCUITS

His contributions here are rooted to:

[6] A. Rodríguez-Vázquez et al., “Chaos from Switched-Capacitor Circuits: Discrete Maps”. Proceedings of the IEEE, Vol. 75, pp. 1090-1106, IEEE August 1987.

[7] A. Rodríguez-Vázquez et al., “A Modular Programmable CMOS Analog Fuzzy Controller Chip”. IEEE Trans. on Circuits and Systems - II, Vol. 46, pp. 251-265, March 1999.

[8] A. Rodríguez-Vázquez et al., “On the Design of Voltage-Controlled Sinusoidal Oscillators using OTAs”. IEEE Transactions on Circuits and Systems, Vol. 37, pp. 198-211, IEEE February 1990.

Pub [6] addressed deterministic chaos synthesis with switched-capacitor circuits. Concepts were extended to continuous-time circuits in several IEEE Trans. on Circuits and Systems papers and supported a system implementation of chaos-based communications, reported in IEEE Journal of Solid-State Circuits, Vol. 40, pp. 1460-1472, July 2005. Pub [7] contributed systematic procedures for adaptive nonlinear function interpolation with fuzzy basis functions which enabled fully adaptive controller chips reported in IEEE Micro and IEEE Trans. on Neural Networks. Finally. Pub [9] addressed fundamental problems concerning signal generation by electronic circuits. Methods and procedures devised there are being crucial for the latest activities of Prof. Rodríguez-Vázquez´s group on time-encoding architectures for sensor front-ends and Time-of-Flight signgle-photon imagers.

ANALOG-TO-DIGITAL CONVERSION WITH EMPHASIS ON OVERSAMPLED DATA CONVERTERS

The book:

[9] A. Rodríguez-Vázquez et al., CMOS Telecom Data Converters. ISBN 978-1-4020-7546-9, Kluwer Academic Publishers 2003.

is representative of Prof. Rodriguez-Vázquez´s contributions, besides two other books and several Trans. on Circuits and Systems and IEEE Journal of Solid-State Circuits papers. Most significant achievements were innovative design methodologies that enabled sigma-delta data converter ICs with optimum Figure-of-Merit values concerning power consumption and resolution. New architectures and methods were embedded in commercial chips produced by different companies, namely: STMicroelectronics for ADSL+, AMIs for automotive, Landy&Gyr for metering and KDPoF for high-speed communications.

BIO-MEDICAL AND BIO-INSPIRED CIRCUITS AND SYSTEMS

Concurrency and adaptability are underlying vision chip architectures. Recently Prof. Rodriguez-Vázquez is also addressing endeavors on neural recording that capitalize previous concepts explored for image arrays. Complete recording system with embedded calibration and feature extraction are contributed in

[10] M. Delgado-Restituto, A. Rodríguez-Pérez, A. Darie, C. Soto-Sánchez, E. Fernández-Jover and A. Rodríguez-Vázquez, "System-Level Design of a 64-Channel Low Power Neural Spike Recording Sensor". IEEE Trans. on Biomedical Circuits and Systems. Vol. 11, pp. 420-432, April 2017.

Overall Dr. Rodríguez-Vázquez has presented some 50 invited plenary lectures at different international conferences. He has co-authored 11 books, 36 additional book chapters, 163 journal papers and some 400 conference papers. Out of his 163 journal papers, 77 are in IEEE journals with a larger concentration on:

• IEEE Transactions on Circuits and Systems: 33 papers
  
• IEEE Journal of Solid-State Circuits: 18 papers
  
• IEEE Sensors Journal: 9 papers
  
• Proceedings of the IEEE: 3 papers
  

His research work has received some 9,400 citations; he has an h-index of 47 and an i10-index of 192 according to Google Scholar.