CE Pro May 2021 - 22

HDMI CORNER by DPL Labs

Networking+Home Control

The HDMI Performance Revolution
Is Finally Ready to Begin
IT IS OFFICIAL: cable manufacturers worldwide now
have available to them the
necessary tools and test
instruments designed specifically for mass-production
cable houses. High Speed
Digital Video cable producers
have never had the ability to
actually capture these high
data rates in real-time during
final production testing.
Historically, factories have
either produced cables with
continuity testing or - if
they were really good -
they would run the product
up on a display and the operator would watch cartoons
all day. With 48G banging
at our door, the need to
elevate to the next level is
imperative.
But why, and why now?
It's simple - the new specification for 8K has extended
the operating envelope substantially and with that an
increased number of features
is becoming available from
the interface.
The response curve chart
in Fig. 1 provides an easy way
to understand how dynamic
the response is. Green line is
48G 8K and red line is 18G
4K. Listed (in green) are just
some of the features inside
each format. We have pretty
much lived in the 10G to
18G space, but under 48G
we need all that plus the
additional data rates to get
us to 8K and 10K. This is all

doable providing the cable
producers have done their
homework. Take note of the
curves and how the signal
attenuates as the frequency gets higher. As we have
learned so many times, these
curves do not necessarily
have the tendency to offer a
natural and smooth roll off.

which certainly cannot
provide peace of mind for
branded cable companies.
But now with full Time
Domain production testing
and the ability to add in
some generated signal stress,
operators can achieve easy
and accurate results. Notice
all four video channels are

COURTESY OF DPL LABS

Even comparing cables from
the same dye lot and build,
there are differences. This is
why we have always relied
on Time Domain measurements and Eye Pattern
diagrams to verify integrity.
In a production facility
where they construct thousands of cables every day,
the chances of experiencing
differences are even greater,

displayed at the same time in
Fig. 2. Some may do fine with
all four channels but others,
as we know, can fluctuate.
In these cases, by increasing
the stress on each device
even low-quality channels
can be identified very quickly
if the device is truly ready for
delivery. Eye diagrams in Fig
2 are all performing very well.
Notice the yellow area in

the waveform. This is known
as the Mask Margin. It
displays the amount of " safe
zone " area each channel
offers. The larger the safe
zone, the better the performance. It is numerically read
on the screen where it is circled in red. In Fig. 2 there are
as much as 10% differences
between channels. These are
strong channels up toward
the 50% level providing
excellent distancing, but
other products may only
hover between 5% to 15%
as a norm. Now factor our
10% differences and you can
see how things can go south
very quickly. Understanding
these numbers allows for
even more scrutiny when
testing each device.
This new production
process has generated
lots of excitement among
manufacturers. They can
now differentiate because
some will practice these new
techniques and some won't.
Price has always been the
motivator, but when it comes
to 48G with 8K and 10K
resolutions this will change.
Now price, reliability and performance can all hold equal
weight when deciding what
cable to buy.
JEFF BOCCACCIO,
president of DPL Labs, can
be reached at info@dpllabs.
com. For more information,
visit dpllabs.com.

22  |  CE Pro May 2021	cepro.com

C2105 pp22 HDMI Corner.indd 22

4/6/21 10:37 AM
http://www.dpllabs.com http://www.cepro.com
CE Pro May 2021

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