7-5
IM 704610-01E
Signal Output
7
7.1 DC Output of Jitter Ratio
Average Coefficient of the DC Output Filter
You can take the moving average of the jitter ratio that has been measured. When the
DC output fluctuates due to instability in the measured jitter ratio, this function
suppresses the degree of fluctuation. The jitter ratio that is moving-averaged using the
DC output filter is applied to both the jitter ratio output and the DC output. The jitter ratio
that is moving-averaged is displayed on the numerical display and analog meter, and
sent to DC output. You can set the average coefficient (number of measured values to
be averaged) to be used when performing a moving average in the following range.
Setting range: 1 to 10 (in steps of 1)
Jitter Ratio Correction Coefficient
The specified jitter ratio can undergo 1st order correction per the specified correction
coefficient. Two correction coefficients can be specified,
α
(slope) and
β
(offset value).
The jitter is the value obtained by multiplying the corrected jitter ratio by time T (see
section 2.3). The corrected jitter and jitter ratio are displayed on the numerical display
and analog meter, and sent to DC output. For the correction equation, see section 2.6.
Setting Range
• Correction coefficient
α
: 0.0001 to 9.9999 (in steps of 0.0001)
• Correction coefficient
β
: –9.999 to 9.999% (in steps of 0.001%)
Note
•
The DC output is 5 V when the trigger is not activated from the measurement input signal
(RF signal) and measurements cannot be made.
•
If the clock cannot be regenerated by the PLL circuit during D-to-C jitter measurement
(PLL unlock), jitter ratio output and determination output are set to 5 V and 0 V
respectively.
•
If the average coefficient for the DC output filter or the jitter ratio correction coefficient is
something other than the default value, the letter F is displayed in inverse video on Display
2 to the left of the characters indicating which parameter is being displayed (except when
equalizer boost amount EQ and arming delay time Dly are displayed).
•
When D-to-C high speed calculation is ON (see section 4.9), the jitter ratio that was
moving-averaged with the DC output filter is not applied to either the jitter ratio DC output
or the judgment output.