HP 83480A User Manual

Waveform Measurements
The Waveform Measurement Process
Calculating thresholds
Once the top and base are dened and crossing points located (for eye
diagrams), threshold levels used for timing measurements are calculated.
These thresholds may be the IEEE values of 10, 50, and 90 percent, 20, 50
and 80 percent, or values in percentages or watts or volts that you set. These
thresholds are called upper, middle, and lower thresholds in the Measurement
menu.
These thresholds are used by all timing measurements as they are needed to
determine the
presence of
a
rising
or
falling
edge
.
In
addition,
the
thresholds
are used
by various
measurements.
F
or
example
,
rise
time
is
measured
from the
lower threshold
to the
upper
threshold
of
a
rising
edge
.
P
eriod
and
frequency
measurements
use
the
middle
threshold
as
shown
in Figure
7-5.
Refer
to
Chapter
10
for
information
on
manually
setting the
thresholds.
Figure 7-5. Calculating the 10, 50, and 90 percent thresholds.
7-10

HP 83480A Specifications

General

Brand	HP
Model	83480A
Category	Measuring Instruments
Language	English