IEEE Solid-State Circuits Magazine - Fall 2014 - 42

[Yannis] seems to have a talent for fishing out
very old references, for instance, books in Russian,
written in the sixties, or earlier!-all this, before
the days of Google.

as well as designs which improved
upon the state of the art [12]. When
faced with the fundamental tradeoff
between dynamic range and power, he
turned to companding techniques-
the result was several filters that
achieved high dynamic range [13, 14]
while consuming orders of magnitude lower power dissipation.
An aspect of his work that really
stands out is his dogged determination to get to the bottom of things,
and pursue something to its logical conclusion. His work on the MOS
parametric amplifier is a case in
point. The story goes that after having come up with the idea, he asked a
student to investigate this in the late
eighties-a time when accurate MOS
transistor models suited for analog
design were not yet available, and the
student concluded that "this wouldn't
work". Unconvinced, Yannis made an
early version of the amplifier, first
reported at ISCAS [15]. This turned

Analog Computer [18]

He is extremely conscientious about
acknowledging all those who came
before. Moreover, he seems to have
a talent for fishing out very old
references, for instance, books in
Russian, written in the sixties, or
earlier!-all this, before the days of
Google. One of us, who investigated
power amplifiers for a while, was
handed a thesis in French to read!
Yannis typically worked with few
graduate students at a time, unlike
many of his well-known contemporaries. His was not a group working
towards a single goal, usually the one
considered important by the industry (and most of the academic community) at that particular time. Each
of his students would be working on
problems quite different from that
of the others. The starting point for
some students would be Yannis' own
analysis or a short paper foraying into
an unknown area. Far from being a
manager-professor, he has been personally technically active throughout
his career. He is the sole or the first
author of about a third of his two
hundred odd publications. Of the
numerous awards he has won, the two
Guillemin-Cauer awards and the WRG
Baker prize have been his alone.
Our interaction with Yannis was
during our graduate student years

out to be the foundation for a paper
that received the best paper award at
ISSCC several years later [16].
A characteristic of his papers
is the rigor of analysis, without an
excess of algebra. We believe that
this comes from his having thought
long and hard about the topic at
hand and having developed a high
level of intuition about the same.
Well before meeting him in person,
one of us had read a testimony to
his uncanny intuition as a footnote in a paper [17] by Martin and
Sedra, themselves accomplished
engineers in this area. The footnote,
simultaneously amusing and inspiring, reads "The authors would like
to acknowledge Dr. Y. P. Tsividis,
who in a private conversation, was
largely responsible for convincing
them of this fact before the present
analysis was carried out."
Another characteristic of his publications is the long list of references.

Parametric Amplifier [15]
log()

Moderate Inversion Limit [20]

VGBM = VFB + ψSM +

Log Domain Integrator [19]
Used in [18]

Qr
Cox

Transistor-Only CT
Filter [15]

βψSM - 1 + e β(ψSM - 2φF - Vc )

p
Charges in a MOS Transisor [2]
Switched-Capacitor Filter Equation [3]
T

-EI

D + ED
SkC -

T
Sk

0
- I SkEI SkED

v (t )

∧

qI (t ) =
∧

qD (t )

v I(t )

q(t)

0
SkCv (tk-)

Figure 1: Yannis and his students worked on diverse topics. Starting from circuit design, they moved both "upwards", towards systems and
circuit simulators, as well as "downwards" towards the MOS transistor.

fa l l 2 0 14

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Table of Contents for the Digital Edition of IEEE Solid-State Circuits Magazine - Fall 2014