CMOS comparators: Basic Circuits All Over Again

Dr. Tom Matthews
Chair Electrical & Electronic Engineering Department, CSU Sacramento

Cerent Engineering Science Complex, Salazar Hall 2009A
4:00 PM

Abstract – Regenerative comparators are an important element in many contemporary analog and mixed-signal integrated circuit (IC) designs, including pipelined and flash analog-to-digital converters. The presenter will discuss his experiences with the design of this particular functional block of circuitry, and how a quest to discover what really determines the output of such comparators led all the way back to convolution and Fourier transforms. Some design considerations will be discussed, but the presentation will focus on basic principles of operation and should be accessible to beginning students. An important specification of such comparators is the input offset voltage. The presentation will also show how basic principles of negative feedback can be employed in simulations to accurately determine the offset specification.

Dr. Thomas W. Matthews received the B.S. and M.S. degrees in electrical and electronic engineering from California State University Sacramento in 1978 and 1989, respectively. He received the Ph.D. degree in electrical engineering from University of California Davis in 1994. From 1995-1998 he taught in the Department of Electrical Engineering at San Jose State University. In 1999 he started teaching at California State University Sacramento where he is currently Professor and Chair of the Department of Electrical and Electronic Engineering. He has consulted for Analog Devices in Wilmington, MA and for Intel in Sacramento, CA.