TJ (1E-12) Result
The Jitter mode Total Jitter (TJ) measurement is the measure of the time variation of the rising and falling edges of an eye diagram as these edges affect the crossing points of the eye. Total Jitter represents the combined effects of all components of jitter: Deterministic Jitter (DJ) and Random Jitter (RJ).
TJ has RJ and DJ components. The measurement's label on the Jitter panel includes (in parenthesis) the symbol error rate (BER) at which the measurement is made. For example, TJ (1E–12) indicates that the measurement is at a BER of 1 x 10–12, which is a probability of occurrence of less than 1 part per trillion. This is the default BER value. You can change the BER setting to any value between 1E-1 to 1E-18 by changing the TJ/TI Measurement BER setting that is located in the Advanced Tab of the Configure Jitter Mode Measurements dialog.
Normally, a signal's UI is equal to the sum of its eye width (EW) and total jitter (TJ):
EW (1E−12) = 1UI −TJ (1E−12)
However, on severely degraded PAM4 signals the tails of the jitter histograms may cross. In this case, the sum of the measured EW and TJ may not equal one UI.
If Advanced Eye Analysis (option 401) is installed, you can measure TJ on patterns longer than PRBS16, such as PRBS31, using Advanced Eye Analysis.
More Information
SCPI Command
:MEASure:JITTer:TJ