"Analog design is now little of the rarefied art of manipulating transistors into interesting and sometimes useful configurations."

A. Abidi, ISSCC’98

Given the mature state of circuit theory and analog circuit design, the focus of microelectronics research is shifting and becoming more application-driven. As integrated systems become increasingly complex, analog circuits play a crucial role in the successful realization of systems embedding not only both analog and digital signals, but also different forms of environmental sensing, intelligence, signal processing, and communication. My research focus is on developing analog integrated circuits for applications involving optoelectronics and photonics, and for biomedical devices.

OEICs encompass integrated circuits with embedded optoelectronics and multi-chip assemblies that combine optoelectronics, optical interface circuitry, and mixed-mode VLSI design. Our research addresses the challenges of developing OEICs for applications that combine photonics, optoelectronics and microelectronics. These applications are growing in multitude and span the consumer, industrial, and biomedical sectors. Examples include

Consumer: optical drives, infrared (IR) wireless links, imagers and organic displays

Industrial: optical interconnect and LAN, optical environmental monitoring

Biomedical: biosensors for fluoroscopy and DNA sequencing

Our research is focused on the development and integration of the key building blocks common to these applications:photodetectors, optical preamplifiers, and timing and data recovery circuits. To date, we have developed new spatially-modulated CMOS photodetectors with reduced intersymbol interference, optical preamplifier circuits with improved stability, ambient light rejection, and low voltage operation, and oscillator circuits that are low jitter and robust to system supply noise.

To date, our research has been applied to consumer and industrial applications such as IR wireless links, optical drives, and optical interconnect. In the future, our research will encompass biomedical and photonic applications such as optical biosensor arrays and the development of a ‘lab-on-a-chip’.

	Low-jitter CMOS Ring Oscillator with On-chip Supply Regulation
	A CMOS Photoreceiver Array for Optical Storage
	Experimental Characterization of Substrate Noise in Multi-Channel Monolithic CMOS Photoreceivers

The development of microelectronics for biomedical devices is one of today’s great research opportunities. The field is vast and includes implantable prosthetics, telemetry, biosensors and instrumentation. Typical design challenges include low power and low noise, battery-less operation, and biocompatibility.

To date, we have developed a micropower, programmable filter for hearing aids and an infrared wireless receiver powered only by the received optical signal. Our most recent work has focused on functional electrical stimulation (FES) involving both transcutaneous and implantable stimulation methods . In the future, our research will include EMG sensing, goniometry, analog-to-digital conversion, and RF telemetry. In particular, we hope to leverage our expertise in OEICs to develop biosensors for fluoroscopy and DNA sequencing.

An inductively powered neural prosthetic implant for the conditioning of muscle tissue and for the eventual control and return of physical motion. This project requires research into sensor interface circuitry,  highly efficient RF circuits for telemetric communications and for energy transmission, DC/DC converters, and clock and data recovery circuits.

Our research focuses on the development of analog building blocks in general, and on low-voltage, low-power analog circuits in particular. The development of low-voltage, low-power analog integrated circuits has been driven by the rapid development of portable systems requiring lower power dissipation, and by the continual reduction in operating voltages for modern CMOS technologies due to shrinking feature sizes. 

Low-voltage circuits are often more complex than their traditional counterparts. A comparison between nested-Miller compensation and traditional lead-lag compensation of op amps is a good example. These novel circuit topologies often do not lend themselves to traditional feedback analysis techniques. As such, part of our work involves developing graphical circuit analysis techniques which can be used for the design and analysis of analog circuits.

Research Areas

	Low-voltage low-power circuit techniques
	Circuit design and analysis using graphical techniques
	Nonlinear circuit design and analysis

Interested in graduate school?

I am personally not accepting any new graduate students. However, the  University of Toronto has one of the strongest electronics research groups in the world, and I  encourage you to contact our other professors in the department. You can find a brief description of all the professors and links to their web sites by going to http://www.ece.utoronto.ca. For more information about  applying for graduate studies, please see our Graduate Office web site.   

Research Team

I proudly present for you my current team of bright and motivated students:

Past Students

	Euhan Chong, Monolithic CMOS Photoreceivers  for Optical Storage,M.A.Sc., 2004.
	Natalie Wong, Design of Monolithic CMOS Photoreceivers with Low Substrate Crosstalk for Multi-Channel Applications, M.A.Sc., 2003.
	Louie Pylarinos, A Low-Voltage Low-Power Programmable gm-C Filter Using Dynamic Gate Biasing, M.A.Sc., 2002.
	Tony Pialis, Design and Analysis Techniques for Low-Voltage, Low-Jitter Voltage-Controlled Oscilators, M. Eng., 2002.

Last updated July 06, 2005