Page 10 - Power Electronics News - December 2020

SMART ENERGY
Making smart power a
reality!
By Patrick Le Fèvre, PRBX, Chief Marketing and Communication Officer
As in many other definitions, ‘Smart Power’ has
become a marketing buzz phrase and it’s some-
times hard to understand what the ‘smart’ part
means. Or if we put it another way, - what the
benefits are for the end user. It may be equally
difficult to identify when Smart Power became
trendy, but today, from a power controller IC to
a fully automated factory, Smart Power is every-
where and with the growing Industry 4.0 its posi-
tion as a predominant technology is assured.
10 DECEMBER 2020 | www.powerelectronicsnews.com
THE ORIGIN OF SMART POWER
In the case of the PWM pioneers, ‘Smart Power’
was born in 1976 when Silicon General launched
the famous Pulse Width Modulator SG1524 chip.
But for many of us it was in the mid-nineties
when the semiconductor industry pushed sili-
con boundaries by adding more functionalities to
power control integrated circuits.
In his 1998 book ‘Power electronics design hand-
book low-power components and application’,
Nihal Kulartna considered that the term ‘Smart
Power’ was more relevant when related to in-
creasing functionality levels at chip level, re-
ducing the number of surrounding components
required by the power controller, simplifying de-
sign and reducing the amount of space required
on customers’ boards. Among the additional
functions added to a single chip, at that time we
could name drive circuitry, thermal protection,
over and under voltage protection, current limit-
ing, and diagnostics.
In the late nineties many Smart Power controllers
were developed to meet the demanding environ-
mental and cost constraints of the automotive
and consumer electronics industries requiring
highly integrated levels of functionality to reduce
space and cost.
Although within the semiconductors industry the
definition of Smart Power may have been obvi-
ous, discussions and debates were raging with-
in the power community about ‘Smart Power’
especially when a new technology, the so-called
‘Digital Power’, was also the subject of many
discussions. Diplomatically, Nihal Kulartna con-
cluded that the term ‘Smart Power’ was used for
institutional rather than technical reasons, and
that remains very much the case.
WHEN DIGITAL MAKES POWER
SUPPLIES SMARTER!
For the 21st century power electronics designers,
‘Smart Power’ started with the implementation
of digital power, bringing in a new dimension in
the way that a power supply can be controlled to
optimize overall performance by using microcon-
trollers and software in a ‘smart’ way.
Smart Energy
Although in 2020 Digital Power is an established
part of the power engineer’s toolbox, we should
remember that making power supplies smarter
has been a long quest and we should recognize
the merits of the pioneers who sewed the seeds
of ‘Digital Power’ including Trey Burns, N.R. Miller
and Chris Henze.
Regarding those inventors I would like to mention
an interesting event that took place when the
power industry was starting to slowly consid-
er the migration from linear-power to switching
power using the SG1524 IC. Trey Burns researched
and explored the use of the State-Trajectory
Control Law in step-up DC/DC converters and he
compared two methods of realization, one em-
ploying a digital processor and the other using
analogue computational circuits. The results of
this research were presented at various confer-
ences but PESC 1977 is considered as the origin
of a wave of research into digital methods to
drive, monitor and control DC/DC converters and
power supplies.
It is now anecdotal but nonetheless interesting
to note that an experimental product built by
Trey Burs was a boost converter operating at a
switching frequency of 100Hz. That now sounds
slow, but it had to be so because it took up to
450μsec to execute the digital program per sam-
ple. The digital controller was a PDP 11/45 mi-
ni-computer, and the boost converter was built
using a 10mH cut-C core inductor (very big and
heavy) and approximately 13,000μF of capaci-
tance. The research team pushed the circuitry up
to the computer on a cart.
Following PESC 1977, power engineers made lots
of progress researching how to digitalize power
control, and the years 1984 and 1985 represent
the second cornerstone in the evolution of digital
power technology.
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