[802.3ae_Serial] Serial PMD call Tuesday - Jitter testing
Hi,
In fact my assumption is correct at least with the transponder modules we
have in hand you cannot simply add the 15ps pp to the jitter. The 15 ps I
mentioned in my last mail, was the extreme, however the behaviour against
sinusoidal jitter added we found not to be different between transponders
with higher or lower of such DCD. From this it seems that this effect in
this dimension seems really to be separate to other jitter.
Regards Juergen
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Von: Rahn, Juergen (Juergen)
Gesendet: Dienstag, 22. Januar 2002 16:46
An: stds-802-3-hssg-serialpmd@ieee.org; 'piers_dawe@agilent.com'
Betreff: AW: [802.3ae_Serial] Serial PMD call Tuesday - new test
methods
Hi,
In preparation some more info on the measurement that have been base
for my
presentation at the last meeting.
As I stated during the presentation, the jitter generated between
50KHz and
80MHz was about 0.05 UI PP (exact value up to 0.062 max according
to the
jitter analyzer) and 0.004 UI RMS.
However not visible in here is that the crosspoint of the eye was
shifted.
If this shift is added (it can be interpreted as duty cycle
distortion) it
would give us 15ps PP extra (for those transponders). However while
this is
visible in the eye I do not think that this will generate a penalty
like
something that closes the eye really as this is a crossing shift
only and
may even not be visible at the decision point in relation to the CDR
implementation.
Such effect is also visible in the 1550 feasibility presentation
eye masks
and the effect is stronger at high extinction ratios while we see
BER
penalties at low rates. (Here the eyes really close).
Regards Juergen Rahn
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Von: piers_dawe@agilent.com [SMTP:piers_dawe@agilent.com]
Gesendet: Montag, 21. Januar 2002 17:48
An: stds-802-3-hssg-serialpmd@ieee.org
Betreff: [802.3ae_Serial] Serial PMD call Tuesday - new
test
methods
There will be a PMD teleconference tomorrow at the usual
time where
we will
continue work on the alternative optical test methods
discussed at
last
week's face to face meeting.
Briefly, these are:
Replace jitter bathtub with:
Longer lower eye mask to screen for high probability
events,
and
Transmitter and dispersion penalty measurement using
bit-error ratio
tester to screen for low probability events.
Simplify stressed receiver generation: simulate high
probability
vertical
and horizontal eye closure, and sinusoidal jitter, only.
Suggested
method
of adding a PRBS and an interfering sine wave.
I will try to get some notes to the reflector from last
week's
meeting
before tomorrow's, which will be at:
Usual coordinates:
4:15 pm GMT = 17:15 CET = 11:15 am EST = 8:15 am
PST,
Tuesday
+1(816)650-0631 Access code 39209
Piers