LeCroy SDA - Page 161

SDA Operator’s Manual
Parameter Description Definition Notes
Fall time Fall time: Duration of falling edge
from 90-10%.
Threshold arguments specify two
vertical values on each edge used
to compute fall time. Formulas for
upper and lower values:
lower = lower thresh. x amp/100 +
base
upper = upper thresh. x amp/100 +
base
Time at upper
threshold minus
Time at lower
threshold
averaged over each
falling edge
On signals not having two
major levels (triangle or saw-
tooth waves, for example), top
and base can default to
maximum and minimum,
giving, however, less
predictable results.
Standard parameter.
Fall 80-20% Fall 80-20%: Duration of pulse
waveform's falling transition from
80% to 20%, averaged for all falling
transitions between the cursors.
Average duration of
falling
80-20% transition
On signals not having two
major levels (triangle or saw-
tooth waves, for example), top
and base can default to
maximum and minimum,
giving, however, less
predictable results.
Standard parameter.
Fall@level Fall at level: Duration of pulse
waveform's falling edges between
user-specified transition levels. See
also Rise@level.
Transition time for % or
absolute levels of all
falling edges.
Enhanced version sets
measurement
calculations to use one
of the following:
Base & Top (% or
absolute)
Peak-Peak (%)
0V-Min (%)
On signals not having two
major levels (triangle or saw-
tooth waves, for example), top
and base can default to
maximum and minimum,
giving, however, less
predictable results.
Standard parameter.
Enhanced parameter available
with EMC option.
First Indicates value of horizontal axis at
left cursor.
Horizontal axis value
at left cursor
Indicates location of left
cursor. Cursors are
interchangeable: for example,
the left cursor may be moved
to the right of the right cursor
and first will give the location
of the cursor formerly on the
right, now on left.
Standard parameter.
SDA-OM-E Rev H 161