81250 Datasheet, PDF (13/64 Pages) Keysight Technologies – Agilent ParBERT 81250 Parallel Bit Error Ratio Tester

Fast eye mask
The eye opening measurement as
above reveals a lot of detailed
information but can be time con-
suming, especially when a fine
resolution has been chosen,
which maybe required and toler-
able during the R&D phase, but
probably not during manufactur-
ing. For this purpose the fast eye
mask measurement was devel-
oped. From one up to 32 meas-
urement points can de defined
where the BER shall be meas-
ured. A measurement point is
defined as a pair of sample point
timing and threshold voltage.
Both can be defined in absolute
values or relative to the automat-
ically determined eye opening /
optimum sampling point and
threshold.
Very often six measurement
points are sufficient (see figure 11)
to guarantee a certain pulse/eye
performance. For reasonable
BER values the whole measure-
ment usually only takes a few
seconds.
Figure 10. The fast eye mask setup and results window
Threshold voltage
90%
100%
50%
10%
Measurement results provided:
• BER at pre-defined sample
point and threshold voltage
• pass/fail results
–0.4 _0.16 +0.1 +0.4
Actual sampling point
Figure 11. The fast eye mask setup and results window
Time (UI)
ParBERT 81250 1M3 ain Overview
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