Agilent Technologies 54830 Series Service Manual page 78

c Enter the desired threshold value in the threshold selection box.
Threshold Accuracy Voltage Test Settings
Threshold voltage settings
(in oscilloscope User softkey)
+5.00 V
-5.00 V
0.00 V
Do the following steps for each of the threshold voltage levels shown in the above table.
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a Set the threshold voltage to 5.0 V as described in step 5.
b Enter the corresponding DC offset voltage on the power supply. Use the multimeter to
verify the voltage.
Digital channel activity indicators are displayed in the quick measurement window under the
digital tab.
c Use the knob on the power supply to decrease the offset voltage, in increments of 10
mV, until the activity indicators for the digital channel under test is at the digital low
level. Repeat for all channels or test multiple channels at the same time. Record the
oscilloscope calibration voltage in the performance test record.
d Use the knob on the power supply to increase the offset voltage, in increments of 10 mV,
until the activity indicators for the digital channel under test is at a digital high level.
Repeat for all channels or test multiple channel at the same time. Record the oscilloscope
calibrator voltage in the performance test record.
Before proceeding to the next step, make sure that you have recorded the oscilloscope calibrator
voltage levels for each of the threshold settings shown in Table 3-3.
DC offset voltage setting
(on oscilloscope calibrator)
+5.250 V ±1 mV DC
-4.750 V ±1 mV DC
+100 V ±1 mV DC
Chapter 3: Testing Performance
To verify threshold accuracy
Limits
Lower limit = +4.750 V
Upper limit = +5.250 V
Lower limit = -5.250 V
Upper limit = -4.750 V
Upper limit = +100 mV
Lower limit = -100 mV
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