LeCroy Digital Oscilloscopes, Manual

Page: 172 / 213

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Note: The Glitch SMART
Trigger is the particular variety
selected by default. It will be
used here, but pressing the
menu button for “SETUP
SMART TRIGGER” will show
the other types of SMART
Trigger available.
Source and coupling were set
in the preceding steps. The
slope can now be selected —
“
1HJ
” (negative) or “Pos”
(positive). The icon displayed
under the grid represents and
describes the trigger setup.
The next step is to set the trigger to capture the glitch on the current
signal.
Here, the glitch’s width is lower than the signal’s. Thus the trigger
needs to be set to a smaller width than that of the signal, whose own
width depends on the DC trigger level. If that level is set at the middle
of the sinewave, the width can be considered as the half period.
However, if the level is higher, the signal’s width has to be considered
as being less than the half-period. Two microseconds is the period for
our example sinewave. The DC trigger level is set, not at the middle
of the sinewave, but where its width is about 800 ns.
Therefore, the Glitch SMART trigger ought to be on CH 2 at end of
“Neg” pulse with a width of < 800 ns.