Evaulation_Engineering_March_2020 - 4

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RNELSON@ENDEAVORB2B.COM

NOT YOUR PARENTS'
POWER SUPPLY
	 The programmable power supply has
often been considered an afterthought.
You may need to upgrade your communications test set regularly to meet the latest Wi-Fi
or 3GPP standards, or you may need a new
oscilloscope with higher bandwidth, but when
it comes to power supplies, volts are still volts
and amps are still amps, right?
If this truism were ever correct, it's becoming more and more outdated as applications
such as the IoT and renewable energy and
enabling technologies such as wide-bandgap
power semiconductors come to the fore. As
Ron Wilcox, senior director of power test
engineering at Analog Devices Inc., put it,
"Twenty-five years ago, I did not think one
would be concerned with microvolts and
picoamps in power semiconductor test, but
we now find ourselves measuring just those,
and often in the face of challenges like > 100
VCM or in noisy environments."
"Power supplies continue to become more
specialized," said Bill Griffith, who works in
product marketing at Keysight Technologies.
"Research and design engineers working on
the bench want a quiet power supply with
multiple outputs and a large display. Bench
power supplies need to have a fast transient
response to simulate a battery. System engineers want a high-density power supply that
requires very little space in their ATE rack."
Griffith added that engineers can struggle
to simulate and characterize real-world devices. "Power supplies often require higher
output bandwidth along with better measurement systems for accurately characterizing
devices," he said, adding by way of example,
"IoT devices pull current in short bursts
that are difficult to measure accurately.
Underestimating the power in each burst
can lead to overstated run times."
He added, "The need to test 2-quadrant
devices such as batteries and bidirectional
converters and inverters is increasing. Having
a single solution that can source and sink

current simplifies test setups."
In addition, he said, "For sink-mode applications requiring 5 kW to hundreds of kWs
or more, regenerative power supplies provide
higher efficiency and a smaller footprint. A
regenerative power supply needs less space
as it recycles power back to the grid instead
of dissipating the power locally."
EA Elektro-Automatik managing director
Eric Turner commented on the benefits widebandgap technology brings to power supplies.
"EA Elektro-Automatik's latest generation of
SiC switching devices uses magnetic components with distributed air gaps and profile
winding technology resulting in a reduction
in size that is truly remarkable," Turner said.
He added that control circuitry is continuing
to move from analog to digital. "Digital architecture using FPGA-based controls to the
amplifier improves load-regulation response
and opens the door for additional features like
arbitrary waveform generation and advanced
measurements," he said.
Flexibility in a power-supply system can
be as important as performance, efficiency,
and size. "System flexibility is important since
many of the eMobility and renewable applications are in their early stages of development," said Turner. "Often enough, existing
and certainly future requirements are not
fully understood, so customers want flexibility and modularity."
Griffith also sees a need for flexibility.
"Most automated tests benefit from a modular solution that allows the customization of
individual outputs," he said. "Modules allow
quick reconfiguration to meet the needs of
an evolving test plan."
So if you have some old programmable supplies in your lab, it may be time to reevaluate
them with respect to performance and size as
well as features like bidirectional operation.
For more, see our reports on power semiconductor test and power supplies and loads in
this issue.

17.9 MILLION
Potential number of wafers
per year of new IC capacity
to be added in 2020

20.8 MILLION
Predicted number of wafers
of new IC capacity in 2021
Source: IC Insights

19.8 BILLION
Estimated global printed
electronics market in 2024

15.1%
Expected CAGR of global
printed electronics market
from 2019 to 2024
Source: ResearchAndMarkets.com

36.7 BILLION
Worldwide sales of
semiconductors in
November 2019

10.8%
Year-over-year decrease
in semiconductor sales
in November 2019
Source: SIA

4

EVALUATION ENGINEERING MARCH 2020
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Evaulation_Engineering_March_2020

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