The OUTPUT NORM/COMP switch could also be used to
reverse the upper and lower levels as the trigger edge does,
but some error could be introduced by the X-Y multiplier.
Control Operation
3.2.9
Rise Time Measurements
When measuring rise time in a linear device under test, the
error induced by the rise time of the testing system must be
considered.
on an oscill
For exam
oscope, 80
pie, when
1 rise time
obse
is
rving the 801 rise time
=
+
observed scope 801
O f
MODE CONT
OUTPUT COMP
PERIOD/RATE Set as desired.
and Level Con-
trols
W IDTH Set to desired lower level time (see
figure 3-4). The > 70% pulse will start
W IDTH time after SYNC leading edge
with DELAY OFF.
‘801 =
observed
scope
That is, the observed rise time must be corrected for by the
inherent oscilloscope rise time to determine the actual 801
rise time. Extending the method to include a circuit under
test will determine circuit under test rise time:
+
+
observed
801 scope c.u.t.
Control
S Y N C
COMPLEMENT
>70% D U T Y C Y C L E PULSE
Figure 3-4. Greater Than 70% Duty Cycle Pulse
Operation
3.3
OPERATION
Edge Controls Set as desired.
and DELAY
In the following descriptions of operation, observe the
pulse on an oscilloscope. When the
OUT pulse is not
desired, disregard leading and trailing edge adjustments.
(See figure 3-2 for pulse parameters.)
3.3.1
Continuous Pulses
3.3.3
Triggered Pulses
Set up as in paragraph 3.3.1. If triggering with an external
signal, connect the trigger source to TRIG INPUT. Ensure
that the trigger rate is slower than the pulse rate.
Set the controls as follows for continuous pulse output.
Control Operation
Control Operation
MODE TRIG
MODE CONT
TRIGGER Set as desired. (Observe TRIG indicator
to ensure triggering occurs.)
OUTPUT NORM (or COMP if inverted pulse is
desired)
3.3.4
Gated Pulses
All Other Set as desired. DELAY is constrained to
Controls be less than PERIOD-(WIDTH +TRAIL-
ING EDGE). If a large pulse WIDTH is
desired but cannot be obtained, refer to
paragraph 3.3.2.
3.3.2 Continuous Wide Duty Cycle Pulses
Set up as in paragraph 3.3.1. If gating with an external sig-
nal, connect the gate source to TRIG INPUT. Set the gate
pulse width to allow the number of pulses desired. Reset
the controls as follows.
Control Operation
MODE GATE
Follow this setup for pulses greater than those that can be
obtained in paragraph 3.3.1. The “pulse” that appears to be
positive going is referred to as the > 70% pulse.
TRIGGER Set as desired. (Observe TRIG indicator
to ensure triggering occurs.)
3-5