To Verify Threshold Accuracy - HP 54645A User's And Service Manual

Testing, Adjusting, and Troubleshooting

To verify threshold accuracy

To verify threshold accuracy
Press
1
under the Set
just to the right of
For each of the threshold levels shown in the following table:
2
a
b
c
d
Using the 8-by-2 test connector, connect digital channels D8-D15 to
3
the output of the function generator. Connect the D0-D7 ground lead
to the ground side of the 8-by-2 connector.
Repeat steps 1 and 2, using digital channels D8-D15 for D0-D7.
4
Table 7-3 Threshold Test Settings
Threshold Voltage
+5.0
–5.0
0.0
7-14
Instructions for HP 54645D
These instructions apply only to the HP 54645D Mixed-Signal Oscilloscope.
Label/Threshold
softkey. Then, select the variable threshold softkey
.
ECL
Use the Entry knob on the oscilloscope to select the threshold voltage
shown in the table.
On the function generator front panel, enter the DC offset voltage
shown in the table. Use the multimeter to verify the voltage.
Activity indicators for D0-D7 should show all at a digital high. These
activity indicators appear on the status line at the top of the display
for several seconds after pressing the variable threshold softkey.
Using the Modify down arrow on the function generator, decrease
offset voltage in 10-mV increments until all activity indicators for
digital channels D0-D7 show the digital channels at a digital low.
Record the function generator voltage in the performance test record.
Using the Modify up arrow on the function generator, increase offset
voltage in 10-mV increments until all activity indicators for digital
channels D0-D7 show the digital channels at a digital high. Record the
function generator voltage in the performance test record.
. Select Threshold Menu
DC Offset Voltage
+5.252 V 1 mV DC
–4.748 V 1 mV DC
+0.102 V 1 mV DC
, and select D0-D7