IEEE Solid-State Circuits Magazine - Fall 2014 - 32

Antenna

+
-

Power
Amplifier
Speaker

LC Circuit
(Week 8)

Demodulator
(Week 9)

Voltage Amplifier
(Week 5)
Radio Receiver (Week 10)

Figure 16: First-year students build a radio receiver in the 10th week of the lab, based on
earlier experiments on op amp circuits, LC circuits, and demodulators [70].

have taught circuits to a variety of
audiences, including art students
at the California College of Arts and
Crafts, high school students, and students in my son's first-grade class.
Teaching does wonders for me; it
even picks me up when I am down.
It also teaches me. There is a wellknown quote attributed to Einstein,
"If you cannot explain it simply, you
do not understand it well enough."
This may not apply to all people, but
it certainly applies to me (even if you
leave out the "well enough" part). I
cannot understand an area outside
my own, unless I teach a course on it,
so that I am forced to explain the concepts to others. I have learned signals
and systems, semiconductor devices,
digital signal processing, and communication systems by teaching the

corresponding courses at Columbia.
When I do this, I study from several books (anywhere from three to
seven), trying to come up with my
own synthesis of the subject. It takes
a lot of time and effort, but it pays
in the end, both for the students and
for me. Early in my career, I got the
following comment in one of the
student evaluations: "He can probably explain everything, from tax law
to organic chemistry." I smiled, and
thought, "If you only knew."
In the mid-nineties, I asked my
department to give me a one-semester
leave from teaching, so that I could do
a study to determine why students do
not take well to the first circuits class,
which then was, as in most places, a
circuit analysis class. After studying the opinion of other educators

VOUT > VIN

Nothing
Connected
Here

C
R
C
VIN

VIN
R

(a)

(b)

Figure 17: Passive circuits with voltage gain. (a) RC, (b) MOSFET. The quantities shown are
phasors.

fa l l 2 0 14

IEEE SOLID-STATE CIRCUITS MAGAZINE

on the matter (notably Ron Rohrer's),
and interviewing students, it became
evident that the problem was that
today's students see circuit analysis
as a bunch of equations. They have
no "frame" to attach the subject to (in
contrast to me and many others who
had tinkered as children) and, having
grown up in the age of video games,
are impatient; telling them that they
will find out next year how the subject
can be applied doesn't do it for them.
I decided to introduce a first-year
course in which circuits are introduced
together with electronics at a basic
level, with emphasis on lab (three
hours per week). In the lab sections, I
tried not only to reinforce the utility of
what the students were learning in the
lecture, but also to encourage students
to discover things - in other words,
make them experience, to the extent
possible, the joy hobbyists experience.
It worked. In the course and lab, students build up their understanding
gradually, as exemplified in Fig. 16. I
published the lab manual into a small
book [68], which has helped carry the
approach to a number of other universities. I wrote about this experience
elsewhere [69, 70], so I will not say
more here. But I would like to say one
thing, in order to avoid any misunderstandings: having tinkered can be a
big advantage, but it is not a sufficient
condition for success in our field. Neither is it necessary; some of the mostrespected leaders in IC design had not
tinkered as children.
I encourage students to challenge
their assumptions, or rather to become
aware of assumptions they are making
without realizing it. I do this often by
giving them puzzles. I will mention
some examples. We have a 1 V source
and a 50 X load. What is the value
of the source resistance that results
in maximum power transfer? Nine
out of ten students answer "50 X. "
But if you do this, I tell them, you get
a voltage divider, so only 0.5 V will be
applied to the load. Wouldn't a 0 X
source resistance work better, given
that it would result in a 1 V load voltage, and thus more load power? They
get startled when they hear this; they

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