Appendix B: Automatic Measurements Reference

CSA8000B & TDS8000B User Manual B-11

Table B- 2: Pulse Measurements - Timing (cont.)
Name Definition
Period The time interval between two consecutive crossings on the same slope of the signal at the
mid-reference level.
Period = Tcross3 –Tcross1
Where Tcross3 and Tcross1 are the times of the first two consecutive crossings on the
same slope at the mid-reference level.
The mid-reference level is adjustable and defaults to 50% of the pulse amplitude.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2). See To Localize a Measurement on page 3--83.
See Measurement Reference Parameters and Methods on page B--56 or in the online help and
also see Reference Levels Method on page 3--79.
Phase
Where:
HTcross1 of source1 is the time of the first crossing of either polarity on source 1.
HTcross3 of source1 is the time of the next crossing on source 1of the same polarity as
Tcross1.
HTcross1 of source2 is the time of the first crossing of either polarity on source 2 after
Tcross1 of source1
HAll Tcrossings are at the mid-reference levels, which are adjustable and default to 50%
of the pulse amplitude.
If measurement gates are enabled, the measurement region is constrained between the Start
Gate (G1) and Stop Gate (G2) of the sources.
Phase =Tcross1 of source2 −Tcross1 of source1
Tcross3 of source1 −Tcross1 of source1 ⋅360
Pk-Pk Jitter The delta between the minimum and maximum of time crossings of data sampled at the at the
mid-reference level.
Pk-Pk Jitter = Tcrosspp
Where Tcrosspp is the difference between the maximum crossing time and the minimum
crossing time for a histogram of the Tcross values. Tcross is the horizontal coordinate of
the first positive or negative crossing.
The mid-reference level is adjustable and defaults to 50% of the pulse amplitude.
The slope can be selected to be the first positive, the first negative, or the first crossing (positive
or negative) in the region.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2). By default, the algorithm searches forward from the Start Gate
for the first specified edge, but the Direction of traversal can be reversed, so that the search will
be backward from the Stop Gate.
This measurement requires the use of a waveform database. When this measurement is turned
on, it will automatically set the measurement system to use a waveform database if available.
See Use a Waveform Database on page B--70.