Titre: Tradeoffs and Optimization in Analog CMOS Design
Conférencier: David M. Binkley, University of North Carolina at Charlotte, USA ,
Lieu: École Polytechnique de Montréal , Pavillon Lassonde, M-1420
Date et heure:
vendredi le 30 janvier 2009 de 08:30 à 16:30

Résumé: The three design choices of drain current, channel width, and channel length required for every MOS transistor greatly complicate analog CMOS design, but provide significant opportunities to optimize circuit performance. Use of the inversion coefficient, which is a numerical measure of MOS inversion, enables design freely in weak, moderate, and strong inversion and facilitates optimum design. Here, channel width required for layout is easily found and implicitly considered in performance expressions. This tutorial describes hand expressions and measured data illustrating tradeoffs in MOS device performance, including effective gate-source bias and drain-source saturation voltages, transconductance efficiency, normalized drain-source conductance, capacitances, gain and bandwidth measures, thermal and flicker noise, and mismatch. A simple spreadsheet tool is then used to predict MOS device performance and map this into complete circuit performance.

Tradeoffs and optimization of performance are illustrated first by the design of differential pairs and current mirrors. Then, three, 0.18 m CMOS operational transconductance amplifiers are optimized for DC, balanced, and AC performance. Measured performance shows significant tradeoffs in voltage gain, output resistance, transconductance bandwidth, input-referred flicker noise and offset voltage, and layout area. Because of the technology normalization present when using the inversion coefficient, the design optimization methods presented are readily extended to smaller geometry processes. The methods provide design intuition leading towards optimum design, while minimizing trial-and-error simulations.

Note biographique: David M. Binkley received the B.S., M.S., and Ph.D. degrees in Electrical Engineering from the University of Tennessee, Knoxville. In 2000, he joined the University of North Carolina at Charlotte as a faculty member in the Department of Electrical and Computer Engineering were he conducts research in analog CMOS design methods, including design of micropower, low-noise circuits for neural implants and radiation hardened, deep space applications. Dr. Binkley was cofounder and vice president of integrated circuit development at Concorde Microsystems where he designed CMOS integrated circuits for battery-operated consumer applications and positron emission tomography (PET) medical imaging systems. Prior to that, Dr. Binkley was a senior scientist at CTI PET Systems where he designed discrete and integrated circuits for PET medical imaging systems. Both Concorde Microsystems and CTI PET Systems are now part of Siemens Medical Solutions. Dr. Binkley has given tutorials or invited talks at the Design Automation Conference (DAC), European Conference on Circuit Theory and Design (ECCTD), International Symposium on Circuits and Systems (ISCAS), International Conference Mixed Design of Integrated Circuits and Systems (MIXDES), and the European Solid-State Circuits Conference (ESSCIRC) and was a visiting scientist at the Institute of Electronic Design Automation at the Technical University of Munich. He is the author of Tradeoffs and Optimization in Analog CMOS Design, John Wiley and Sons, Ltd., 2008, which is the first book dedicated to this important topic. Dr. Binkley is the author of over 65 papers in analog circuit design, holds seven U.S. patents, and has conducted research for DARPA, NASA Jet Propulsion Laboratory, and the National Institutes of Health.

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