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Model 4277A
SECTION III
OPTION 001 INTERNAL DC BIAS OPERATION
1. Set the DC BIAS select switch® to INT.
2. Connect the 16047A Test Fixture to the
UNKNOWN terminals.
Note ,
Any of the test fixtures and test leads
listed in Table 1-3 can be used for
measurements requiring dc bias.
3.
Turn on the 4277A.
4.
Perform OPEN and SHORT Zero Offset
adjustments as described
in
paragraph
3-51.
5.
Set the instrument's front panel controls
as
appropriate
for
the
desired
measurement.
6.
Press the FREQ/DC BIAS select key (2).
The DC BIAS lamp will come on.
7.
Set the desired voltage by pressing the
^propriate FREQ/DC BIAS control key
The voltage value will be displayed on
the FREQUENCY/DC BIAS display.
Note
OFF will be briefly displayed on the
FREQUENCY/DC
BIAS display
when
the
FREQ/DC
BIAS
control
key
is
release^ if the
DC
BIAS
ON/OFF
switch ©is set to OFF.
8. Connect the DUT to the test fixture.
CAUTION
DO NOT CONNECT A CHARGED DUT
TO THE TEST FIXTURE,
DOING SO
MAY DAMAGE THE INSTRUMENT.
9. Set the DC BIAS ON/OFF switch ©to ON.
10. If you're measuring a capacitive DUT, all
sufficient time for the DUT to charge up
to the applied voltage.
11. Read the measured values displayed on
DISPLAY A and DISPLAY B.
12. Set the DC BIAS ON/OFF switch ® to
OFF.
13. Wait until the voltage across the DUT
return to OV.
14. Remove the DUT from the test fixture.
Note
For reasons of safety and measurement
accuracy, the voltage actually applied
to the DUT should be monitored. Refer
to Figure 3-32.
Note
When the DC BIAS switch on the front
panel has been set to ON and the
desired bias voltage is entered, the
instrument automatically takes a wait
time
of
approximately
0.8
seconds
before
outputting
the
bias
voltage
(after
completion
of
the
bias
data
input).
Accordingly,
it
takes
approximately
(0.8
seconds
+
bias
settling time) for the bias voltage to be
applied to the DUT as well as to be
settled after the bias data has been
set. For the bias settling time, refer to
Table
1-2 Supplemental Performance
Characteristics.
Figure 3-31. Option 001 Internal DC Bias (Sheet 1 of 3).
3-71
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