March 24, 2011
Speaker: Marcel Pelgrom, research fellow Philips/NXP Semiconductors
Title: The different faces of variability
Abstract: Circuit design greatly depends on the ability to control and reproduce transistor and
process parameters. Variation in processing was in the past countered by defining
process corners: boundaries in parameter variation that accounted for process
tolerances. With the improved control over processing, this batch-to-batch variation is
largely under control.
However, now an additional class of phenomena has appeared: statistical variations.
These variation between otherwise identical components is generally described
by “mis-match” parameters. Some analog ICs with differential operation (e.g.
analog-to-digital converters) were already affected by mismatch. In advanced
technologies every circuit from SRAM cell to an I-Q mixer is affected by statistical
variations.
Next to these static random phenomena also time-dependent variations play an
increasingly important role: variations in supply voltage and temperature and
interference (supply and substrate noise, cross-talk, etc.) are of major importance to
optimize circuit performance. Understanding and mitigating these effects requires
more and more statistical means.
This talk will review some of the statistical effects and discuss the various techniques
that analog designers in the past used to mitigate statistical issues. Lessons from the
analog domain can provide a starting point for the application in the digital domain.
Bio: Marcel Pelgrom received his B.EE, M.Sc and PhD from Twente University, Enschede The Netherlands. In 1979 he joined Philips Research Laboratories, where his research has covered topics as Charge Coupled Devices, MOS matching properties, analog-to-digital conversion, digital image correlation, and various analog building block techniques. He has headed several project teams and was a team leader for high-speed analog-to-digital conversion. From 1996 till 2003 he was a department head for mixed-signal electronics.
Next to various activities concerning industry-academic relations, he is involved as a
research fellow in research on the edge of design and technology.
In 2003 he spent a sabbatical in Stanford University where he was appointed a
consulting professor. Since 2007 he is a member of the technical staff of NXP
Semiconductors.
Dr. Pelgrom is an IEEE Distinguished Lecturer, has written over 40 publications,
five book chapters and holds 30 US patents. He is lecturing at Twente and Delft
Universities, and for MEAD Inc. In August 2010 Springer published the lecture notes
as a book: “Analog-to-digital conversion”