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2-4
IM 704610-01E
2.3 Measurement Functions (Measurement Items)
Pulse Width Jitter <<For procedures, see section 4.1>>
Pulse Width Measurement
You can measures the pulse width from the rising edge of the slope* to the next falling
edge of the slope (positive side) or from the falling edge of the slope to the next rising
edge of the slope (negative side) of the data signal.
* The slope of a signal is its movement from a low level to a high level (rising), or from a high
level to a low level (falling).
Data
signal
Example of positive side pulses
Measurement Measurement Measurement Measurement
Jitter σ , Jitter Ratio σ /T, and Average Value
A histogram (frequency distribution) is created from multiple pulse widths within a
specified range (see “Upper and Lower Limits of the Pulse Width” on page 2-6), and the
standard deviation
σ
of the values making up the histogram is calculated. This standard
deviation σ is the pulse width jitter. The percentage calculated when dividing the
standard deviation
σ
by the difference T in the upper and lower limits of the pulse width
is called the pulse width jitter ratio. The time-averaged value of the measured pulse
width signal is the pulse width average value (AVE).
T: Difference between the upper and lower limit of
the pulse width.
σ =
Σ
(X
i
– AVE)
2
× P
i
n
i = 1
AVE =
Σ (
X
i
× P
i
)
n
i = 1
n: Number of bins (histogram lines) of the histogram
X
i
: Class value of each bin
P
i
: Relative frequency
(Ratio of frequency X
i
of a single bin with respect to the
total number of samples)
• Pulse width jitter ratio
• Pulse width average value
σ
T
× 100(%)
• Pulse width jitter
Note
By switching the displayed numerical value (see section 5.2) and making queries through
communication commands (see section 10.2.2) you can obtain statistical values other than
the jitter, jitter ratio, and average value.