Affiliation: VLSI Design and Education Center, The University of Tokyo
New Paradigm of Mixed Signal LSI based on Time-domain Circuits for Extremely-scaled Technologies
From a view point of mixed signal LSI designers, one of the special features of extremely-scaled future LSI technologies is a rapid degradation of the dynamic range for analog circuits. Designers are requested to find an optimal solution of analog circuits operating at a lowered supply voltage and a noisy environment due to digital circuits. Since the supply voltage is lowered but device speed is enhanced in scaled technologies, a possible solution for mixed signal design is the time-domain approach, instead of the conventional voltage/current-domain approaches. Time-domain circuits have a superior feature from a view point of the dynamic range and the power consumption, especially in a low voltage operation of scaled devices with high cut-off frequencies.
In this presentation, after discussing a trade-off between the voltage-domain and time-domain in terms of the dynamic range, the current status of the time-domain circuits will be reviewed, focusing on TDA (Time-Difference-Amplifiers) and TDC (Time-to-Digital Converters). Typical applications of the time-domain approach such as PLL and CDR (Clock-Data-Recovery circuits) will be also described to show a feasibility of the time-domain approach.
Kunihiro Asada received the B. S., M. S., and Ph.D. from University of Tokyo in 1975, 1977, and 1980, respectively. In 1980 he joined the Faculty of Engineering, University of Tokyo. From 1985 to 1986 he stayed at Edinburgh University as a visiting scholar. From 1990 to 1992 he served as the Editor of IEICE Transactions on Electronics. In 1996 he established VDEC in University of Tokyo. He served as the Chair of IEEE/SSCS Japan Chapter in 2001-2002 and the Chair of IEEE Japan Chapter Operation Committee in 2007-2008. He is currently professor, director of VDEC. His research interest is design and evaluation of integrated systems and component devices. He is a member of IEEE, IEICE and IEEJ.