IEEE Solid-State Circuits Magazine - Summer 2017 - 48

SSCS webinar program speaker Dr. Matt
Straayer (right) receiving a certificate of
appreciation from the SCV-SSCS Chapter
chair at Texas Instruments in Santa Clara.

A video recording of this event will
be available as an SSCS webinar to all
SSCS members, and Arbabian will be
available after the webinar to answer
questions online. Society members
will receive an e-mail later with the
date and details of this event.

Abstract
Advances in health-care technologies have focused on therapeutics,
interventional procedures, and diagnostics. These treatment steps have
undergone significant improvements,
leading to higher survival rates and
enhancements in quality of life. Nevertheless, current trends are unsustainable due to inefficiency in addressing
specific critical diseases and skyrocketing national health-care costs. An
important example is cancer, where
mortality rates have not seen major
improvements, even with the tremendous technological advances in
diagnostic imaging tools over the last
four decades.
Preventive screening and continuous monitoring have the potential
to completely change the landscape
in the war against cancer and other
complex disease states. Today, the
human body is monitored/screened
infrequently, in contrast with ad-

SU M M E R 2 0 17

vanced electronic systems (many of
which our community designs and
ships), which are routinely and frequently monitored and calibrated.
At best, patients only receive annual
checkups with extremely low "resolution." How do we bring new screening and monitoring technologies
closer to the patients (i.e., consumers)? This talk summarizes our work
in this general space, from new directions in low-cost, portable, and
semiconductor-based, RF-ultrasound
hybrid tricorder imaging systems, to
ultrasound-powered implantable devices that can measure, detect, and
act upon local physiological changes
through closed-loop neuromodulation
or electroceuticals.

"Part 1: Time-Based Circuits-
Not Just the Single Slope!"
As part of the SSCS webinar program,
the SCV-SSCS organized a comprehensive two-part seminar series on timebased circuits. The material from these
seminars will be available on the Silicon
Valley Chapter website and the video
recording will be broadcast as a webinar to SSCS members in early 2018.
Part 1 of this seminar series was recorded on 18 May by Dr. Matt Straayer from
Maxim Integrated Inc., "Time-Based Circuits-Not Just the Single Slope!" Part 2
was held on 17 August by Prof. Pavan
Hanumolu from the University of Illinois, Urbana-Champaign, "Applications
of Time-Based Circuits in Data Conversion, Filtering, and Control."
Straayer started his talk by presenting the benefits of time-based
circuits, specifically that time-based
signals translate to binary levels and
process technology benefits binary
signal processing through small area,
low power, and high speed. This could
have potential assets for many applications including frequency generation, analog-to-digital conversion, and
switched-mode power using pulsewidth modulation. An introduction to
time-based circuits and their properties and a comparison with voltage or

IEEE SOLID-STATE CIRCUITS MAGAZINE

current domain signals followed next.
Basic signal conversion from voltage
and current domains (V&I) to timedomain and basic circuitry used for
this conversion were discussed. V&I to
frequency and time to V&I conversions
and their corresponding circuitry were
also presented.
Details of the time-to-digital converter (TDC) circuitry including classic linear TDC, Vernier TDC, two-step
TDC, and their implementation details
were covered next. The speaker concluded by discussing applications of
time-based circuits in digital phaselocked loop, voltage-controlled oscillator -based analog-to-digital, and buck
converters. The examples and tutorials for this section are available online
at http://www.cppsim.com. A list of
related references and recent publications, which were done in collaboration with Dr. Michael Perrott and Prof.
Pavan Hanumolu, are also available.

Abstract
Compared to circuits utilizing voltage or current to convey analog signals, time-based circuits offer unique
attributes, ranging from simple, areaefficient quantization to more complex
techniques for time-based processing
such as integration, interpolation, and
noise shaping. Although time-based
circuits are not new, the availability of
fast, low-power transistors in advanced
process nodes, combined with the challenges of traditional analog design techniques, has renewed interest in time as
a signal domain both in academia and
in industry. This talk will look at some
obvious and more subtle differences
between voltage and time-based circuits and discuss tradeoffs in the context of application requirements. A few
advanced state-of-the-art time-based
circuits will motivate the audience to
consider how time-based circuits can
be a useful tool for their own designs.

-Mojtaba Sharifzadeh
Chair, Santa Clara SSCS Chapter

http://www.cppsim.com

Table of Contents for the Digital Edition of IEEE Solid-State Circuits Magazine - Summer 2017