IEEE Solid-States Circuits Magazine - Spring 2020 - 22

Although Bult formally gave up teaching
when he left UCLA, his office and whiteboard
became a temple of knowledge for young
analog designers.

FIGURE 1: Klaas Bult and some of his colleagues at a 1997 Broadcom holiday party.
(from left): Henry Nicholas, Henry Samueli, Mehdi Hatamian, Steve Tsubota, and Bult.
(Photo courtesy of Mark Berman.)

of dollars of company revenue. He
recruited and became a mentor to
countless analog engineers. Although
Bult formally gave up teaching when
he left UCLA, his office and whiteboard became a temple of knowledge for young analog designers who
marched in to hear his pearls of wisdom every day.
The team's ADC and digital-to analog converter (DAC) designs
re--gularly set industry benchmarks
in performance. The beauty and
elegance of their work was demonstrated by the fact that from generation to generation they were able to
scale area, speed, and power at least
as well as what was achieved in the
corresponding digital circuits that
tracked Moore's law. The digital circuits simply leveraged scaling, and

S P R I N G 2 0 2 0

the analog circuits took advantage
of scaling for faster transistors as
well, but we also needed to cleverly
apply novel architectures and circuit
designs to overcome lower operating voltages and challenges with
process parameter variations. Over
time, multigigasample-per-second
embedded ADCs and DACs became
the norm in wired broadband communication systems.
The intermediate frequency (IF)
sampled architecture in the pioneering paper mentioned evolved into
direct-sampled architectures with
no IF conversions, thereby achieving the holy grail of true single-chip
digital receivers and transmitters.
These converter designs found their
way into a broad array of Broadcom
products including set-top boxes for

IEEE SOLID-STATE CIRCUITS MAGAZINE

satellite and cable TV, cable modems,
digital subscriber line and passive
optical network transceivers, Ethernet transceivers, and high-speed
serializer/deserializer transceivers
used in networking applications.
These products operate at speeds of
several gigabits per second to several hundred gigabits per second,
and many incorporate broadband
ADC and DAC circuit techniques that
trace back to Bult's innovations.
The word "no" was not in Bult's
vocabulary. Whatever design challenge you placed in front of him, he
would gladly take it on and come up
with extraordinarily creative solutions. Bult is a very practical handson engineer. He truly understands
what it takes to bring a mixed-signal
SoC to mass production without any
excess yield fallout due to the analog circuits. He is virtually an analog
magician in his ability to develop
clever circuits to solve every problem
he faces. I have worked with many
great analog engineers over the
years, but, if I had to pick one person
to "bet the farm on" to design a challenging analog circuit, it would be
Klaas Bult. I want to personally congratulate Bult on receiving the Donald O. Pederson Award from the IEEE
Solid-State Circuits Society. This is a
wonderful recognition of his remarkable accomplishments, and he very
deservedly joins this prestigious
group of honorees.

About the Author
Henry Samueli received his B.S., M.S.,
and Ph.D. degrees in electrical engineering from the University of California, Los Angeles (UCLA). He has
been a professor in the Electrical and
Computer Engineering Department
at UCLA since 1985. He cofounded
Broadcom Corporation in 1991 and
took a leave of absence from UCLA in
1995 to be at Broadcom full time. In
2018, two years after Broadcom was
acquired by Avago Technologies and
renamed Broadcom Inc., he retired
as chief technology officer and now
serves as chair of the board.

IEEE Solid-States Circuits Magazine - Spring 2020

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