5348 Whitepaper

Radiance Pro 5348 Introduction January 24, 2021
viewing distance (typically 1X screen width for 4k). If you cannot see a noise reduction at
viewing distance, any improvement is moot.
We have customers who say they can see a visible improvement due to lower noise using
an external linear power supply and I believe I saw a slight image improvement (lower
background noise) using the 5348 versus the 4446 in the Lumagen Demo Theater RS4500
with the supplied Radiance Pro external digital power supply. These difference are small,
and unlike the audio where I am convinced I could tell the difference in a blind test, for
video the difference would be difficult to tell which technology is in play in a blind test
(IMO). So, we are not claiming you will see a visible improvement on an analog projector
chip such as used by Sony and JVC. However, I believe I did see an improvement, and you
can test this for yourself, assuming you have both a 4XXX and a 5348. I admit this may be
hard to accomplish for most people.
The Radiance Pro 5348 uses a HDMI PLL re-clocking chip on each of the three outputs. We
believe this HDMI buffer integrated circuit has slightly slower output edge rates that will be
more forgiving when used with projectors with marginal HDMI input designs. These chips
reduce jitter, and edge rate, but they also give the 5348 control of the output signal for level
and EQ. Note that the default for the 5348 is to not have output EQ. The 4XXX series always
have output EQ.
In the Lumagen demo theater all supported combinations of 5348 level and EQ work well.
Not having EQ is intended to assist active fiber cables which do not have the appropriate
amount of attenuation in their input buffers to account for the fact that normal HDMI
outputs have cable EQ. This EQ typically in HDMI outputs, and the output edge rate, must
be attenuated by a cable, or a well-designed input buffer in the case of the active fiber cable.
With the default “no EQ” setting a passive cable should be in the 2-meter to 3-meter length
range.
For a projector with a marginal HDMI input design we believe this programmability may
help the projector lock on to an 18 GHz HDMI video signal. This assertion remains to be
proven, or disproven. Note that we are looking for test cases for this. So, if you have a
projector with a marginal HDMI input design that has issues locking on after a signal
change, please contact me and we can discuss if it may be possible to test with the Radiance
Pro 5348 in your problem system.
FAQ:
It was mentioned the 5348 uses the 4XXX software. Might this situation change?
We are evaluating whether it makes sense to have a different FPGA load with better
precision but dropping one or more feature(s) to make room. Two possibilities are
eliminating the reserved gates for PiP/PoP, and eliminating Vertical Keystone correction.
We will not make any decision on this until after the pipeline enhancements currently
being worked on are completed. If we do a special FPGA release it would be a for-a-fee
upgrade enabled by a software key.