Research
Seminars
Spring 2008
Philip K.T. Mok
Associate Professor,
Department of
Electronic and Computer Engineering
Hong Kong
University of Science and Technology
Time : 2:00 - 4:00PM
Date : 18th April 2008
Venue : 834 Mudd Building, Columbia University
All welcome, including non-IEEE members !
The ISSCC offers
local SSCS chapters the opportunity to replay ISSCC tutorials,
short courses and sessions based on the DVD recordings. We will
play the "Embedded Power-Management Circuits" Tutorial by Prof.
P. Mok from the ISSCC'07 in this event.
Tutorial Abstract :
Due to the drastic increase of system integration and power consumption
of an IC with technology scaling, power management becomes a critical
issue in determining the overall performance of the IC. This tutorial
starts with a brief overview of power management circuits for embedded
applications. There follows a detailed explanation of the
operation and design issues associated with various on-chip power
converter circuits including linear regulator, switched-inductor
regulator, and switched-capacitor regulator. The focus is on the
analog circuit techniques, and the control mechanism for implementing
these power converters.
------------------------------------------------------------------------------------------------------------------------------------
Prof. Gu-Yeon Wei
Harvard University
Date : 2:00 PM, Friday, April 11,
2008
Place : Mudd 633
Title
: Combining Circuits + Architecture to Combat Variability in
Nanoscale CMOS
Abstract:
Variability is poised to severely degrade performance and power
scalability of circuits and systems in nanoscale CMOS technologies.
Process, voltage, and temperature variations are well-known effects
that occur across wide temporal and spatial scales. With
aggressive technology scaling, traditional worst-case design techniques
incur large overheads. Higher-level solutions, combined with
innovations at the circuit level, offer a holistic approach that should
combat and mitigate the detrimental effects of variablity. This
talk presents a broad perspective of how we leverage collaborations
between circuits and architecture to address varibility in different
contexts.
Random and systematic variation can can degrade power and performance
of digital systems. This talk introduces ReVIVaL, which
incorporates two techniques to combat variability---voltage
interpolation and variable latency. When applied to a 6-stage
floating-point unit (FPU), experimental results from a 130nm test chip
demonstrate how these techniques can compensate for random and
correlated device-level variations without compromising performance. We
also explore the potential benefits of ReVIVaL extended to a CMP
system. Besides process variation, voltage variation can also degrade
performance scalability and require power overheads. Hence, we
investigate the potential energy savings offered by temporally
fine-grained, per-core DVFS using integrated on-chip switching
regulators. Our analysis suggests energy savings are possible
through fast, per-core DVFS despite the overheads associated with
lower-effiency on-chip regulators. Finally, I will summarize other
research efforts we have on-going at Harvard.
Bio:
Gu-Yeon Wei joined Harvard University in January 2002 and is currently
an Associate Professor of Electrical Engineering. Prior to joining
Harvard, he spent 18 months at Accelerant Networks in Beaverton,
Oregon. Professor Wei received his BS, MS, and PhD degrees in
Electrical Engineering all from Stanford University in 1994, 1997, and
2001. His current research interests are in the areas of
mixed-signal VLSI
circuits and systems design for high-speed/low-power wireline data
communication, energy-efficient computing devices for sensor networks,
and collaborative software + architecture + circuit techniques to
overcome variability in nanoscale IC technologies.
Host: Ken Shepard, shepard
AT ee DOT columbia DOT edu, 212-854-2529
------------------------------------------------------------------------------------------------------------------------------------
|
Prof. Patrick
Chiang
Oregon State
University
Date: 2:30 PM, Friday, April 4, 2008
Place: Interschool Lab, CEPSR 750
Title
: Parallel-Arrayed, Power-Optimal, Process-Calibrating, Interconnect
Circuits for Future Multi-Core Computing
Abstract:
Future
"end-of-scaling" CMOS technologies are characterized by three major
themes: 1)abundant transistors, such that they can be placed
almost anywhere with little cost; 2)power constrained,
exacerbated by the cease in supply scaling; 3) process variant, where
what you simulate is not what you get. In addition, passive
interconnect (both on-die and off-die) exhibit degraded performance
relative to transistor scaling, making interconnect circuits one of the
key circuit blocks that exhibit firsthand these three scaling
constraints. Multi-core computing can improve parallel performance only
at the expense of larger reliance on interconnect circuits.
Therefore, the design of interconnect circuits that can address these
three issues is paramount. In this talk, I will describe a number of
ways the VLSI group at Oregon State is tackling these three key
problems. First, leveraging past work, I will describe a few ways
we have recently addressed these issues, resulting in a few initial
(but un-measured) 65nm CMOS prototypes: 10GSs, 4-bit, 35mW ADC
using resonant clocking; 10 parallel, 10Gbps Transmitters dissipating
40mW. Finally, I will describe future areas of research that we
believe are key circuit challenges for future interconnect-limited,
parallel architectures - SRAMs, crossbars, on-die serial links, off-die
serial links, ADCs, and speed-of-light circuits.
Bio:
Patrick Chiang
received the B.S. degree in electrical engineering and computer
sciences from the University of California, Berkeley, in 1998, and the
M.S. and Ph.D. degrees in electrical engineering from Stanford
University in 2001 and 2007. He is currently an assistant
professor of electrical and computer engineering at Oregon State
University. In 1998, he was with Datapath Systems (now LSI Logic),
working on analog front-ends for DSL chipsets. In 2002 he was a
research intern at Velio Communications(now Rambus) working on 10GHz
clock synthesis architectures. In 2004 he was a consultant at startup
Telegent Systems, evaluating low phase noise VCOs for CMOS mobile TV
tuners. In 2006 he was a visiting NSF postdoctoral researcher at
Tsinghua University, China, investigating low power, low voltage RF
transceivers. In Summer 2007, he was a visiting professor at the
Institute of Computing Technology, Chinese Academy of Sciences, where
he collaborated on the design of multi-gigahertz ADCs and high speed
serial links.
His interests are in the design and implementation of new architectures
for mixed signal circuits in deep submicron CMOS, focusing specifically
on low power consumption and process compensation techniques.
Host: Ken Shepard, shepard
AT ee DOT columbia DOT edu,
212-854-2529
------------------------------------------------------------------------------------------------------------------------------------
Prof. Ranjit
Gharpurey
University of Texas
at Austin
Date: 2pm, Monday, March 17, 2008
Place: EE Conference Room 1312 S.W. Mudd
Title:
Low-power, Interference Insensitive Radio Front-end Architectures
Abstract:
The problem of
interference continues to become progressively severe in modern
wireless systems, owing to greater utilization of spectrum.
Simultaneously, the data rate in many systems continue to increase.
Radio front-ends for such systems thus have to satisfy ever more
stringent dynamic range requirements. This can pose an especially
severe challenge in short-channel CMOS implementations, due to the
relatively low supply voltages of these technologies.
Radio front-end architectures that can alleviate the above dynamic
range challenge are presented in this talk. We begin by examining a
low-power recursive radio front-end topology, that utilizes
transconductance at multiple frequencies. The next part of the talk
addresses our recent work in the area of radio front-ends that utilize
feedforward auxiliary paths to cancel interferers at critical points
with the receiver chain. The technique can be used for canceling
multiple narrowband interferers as well as for achieving broadband
attenuation, without the use of external passive SAW or ceramic filters
and with minimal impact on in-band sensitivity. Recent work on
combining active cancellation with interference detection is presented.
An architecture for broadband interference sensing, that utilizes a
cascade of image reject stages is also discussed.
It is expected that many of these approaches will be useful in emerging
broadband wireless systems as well as Cognitive Radio and Software
Defined Radio systems.
Bio:
Dr. Ranjit
Gharpurey is with the Dept of Electrical and Computer Engineering at
the University of Texas at Austin. He received his PhD from the
University of California at Berkeley in 1995 and his B. Tech from the
Indian Institute of Technology, Kharagpur in 1990. His areas of
research interest include RF and high-frequency analog IC design.
Dr. Gharpurey is currently serving on the technical program committees
of CICC, ISSCC and RFIC conferences, and is an associate editor of the
IEEE Journal of Solid State Circuits.
Host: Peter Kinget kinget
AT ee DOT columbia DOT edu
+1-212-854-0309
---------------------------------------------------------------------------------------------------------------------------------------
March 3 2008:
4pm-7.30pm
Inauguration
of the
IEEE NY EDS/SSCS Chapter
Speakers:
- Jan Van der Spiegel, SSCS Welcome
- Jan Rabaey, Scaling the Power Wall
- Juin Liou, Advanced ESD Protection in BiCMOS/CMOS technologies
- David Weiss, NY Section President's Welcome
Details at: http://edssscs.googlepages.com
---------------------------------------------------------------------------------------------------------------------------------------
Prof. Harris
CISL at Columbia
University
Date: 2pm, Friday, Jan. 25, 2008
Place: EE conference room 1312 S.W. Mudd
Title:
Biologically Inspired Sensing and Coding of Signals
We discuss the role
of biologically inspired spike representations in various engineering
applications including sensor design, time-based signal processing, and
power-efficient
neural recording circuitry for brainmachine interfaces. These
spike-based systems are
shown to outperform conventional approaches in terms of various
performance metrics such
as power consumption, size, SNR, signal bandwidth and dynamic range. We
also consider the
implications this work has on our understanding of neurobiological
systems.
Speaker Bio:
Dr. John G. Harris received his BS and MS degrees in Electrical
Engineering from MIT in
1983 and 1986. He earned his PhD from Caltech in the interdisciplinary
Computation and
Neural Systems program in 1991. After a two-year postdoc at the MIT AI
lab, Dr Harris
joined the Electrical and Computer Engineering Department at the
University of Florida
(UF). He is currently a full professor and leads the Hybrid Signal
Processing Group in
researching biologically-inspired circuits, architectures and
algorithms for sensing and
signal processing. Dr. Harris has published over 100 research papers
and patents in this
area. He co-directs the Computational NeuroEngineering Lab and has a
joint appointment in
the Biomedical Engineering Department at UF.
Sponsored jointly by the Bionet Group (EE), CISL (EE) and LIINC Lab
(BME)
------------------------------------------------------------------------------------------------------------------------------------
|