SECTION2
Operation
Pulse
#1
jE-On~
Level
----+r---""*'
IE-
Off
----"l
Pulse
#2
IE-
On~
IE--
Off
----"l
+
Pulse
#3
!E-on~
IE--
Off~
Pulse
#500
!E-on~
r-Off~
Bias
-7--__.
i i
i
T
i
T .
..
-
j
j
+--Bias
Measure Measure Measure
Measure Measure
Measure
#6
Measure
Measure
X
=
Measurement
point
#1
#2
#3
#4
#5
#999
#1000
Figure
2-34.
Pulse
Waveform
level
is
determined
by
the off time. Notice that there are
two measurements for each pulse; one at the
"on" level
and one at the following bias
("off")
level.
Linear Staircase
Pulse Sweep:
As
shown
in
Figure 2-35,
this pulse sweep steps from a starting pulse level to
an
ending (stop) pulse level. The programmable parameters
of
this
sweep include; start pulse level, stop pulse level,
step, pulse
on
time, pulse off time, bias,
and
source range.
When this sweep
is triggered to start, the
output
will im-
mediately go from the bias level to the
"on"
level of the
first pulse. Subsequent pulse levels
will
be incremented
(or decremented)
by
the step value until the stop pulse
level
is
reached. The time duration
at
each pulse level
is
determined
by
the
on
time. The time duration
at
the bias
level,
is
determined
by
the off time. Notice that there are
two measurements for each pulse; one at the
"on" level
and
one at the following bias ("off")
level.
Logarithmic Staircase Pulse Sweep:
This sweep
is
simi-
lar to the preceding pulse staircase sweep, however the
2-58
+
steps are done
on
a logarithmic scale as shown
in
the ex-
ample sweep in Figure
2-36.
The programmable parame-
ters of
this
sweep include; start pulse level, stop pulse
level, number of pulses
per
decade, pulse on time, pulse
off time, bias,
and
source range.
When this sweep
is
triggered to start, the output
will
go
from the bias level to the start source level. The start level
and
the programmed
points/
decade
(5,
10,
25
or
50)
de-
termine the step values for the staircase. The
Source
Measure
Unit
will automatically select step values that
will provide symmetrical steps (on log scale) through
each source decade to the stop source level. The sweep
example
in
Figure 2-36
is
programmed for 5
points/
dec-
ade. Thus, the Source Measure Unit
selects step values
that provide a five-step staircase through the source dec-
ade.
The time duration
at
each pulse level
is
determined
by
the programmed
"on" time. The time duration at the bias
level,
is
determined
by
the
"off''
time. Notice that there
are
two
measurements for each pulse; one
at
the
"on"
level
and
one
at
the following bias ("off'') level.
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