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3-6
Basic Operation
Model 2520 User’s Manual
Polarity
Polarity for the laser diode current source, both detector current measurements, and laser
diode voltage measurement can be controlled by using the POLARITY selections in the
corresponding configuration menus (see
“Configuring sources,” page 3-9
, for procedures to set the polarity).
Laser diode current source polarity
shows a comparison of positive and negative current source polarity. With the
positive polarity shown in A, current across the DUT develops a voltage such that the pos-
itive DUT terminal is connected to CURRENT OUTPUT HI, and the negative DUT termi-
nal is connected to CURRENT OUTPUT LO. With the negative polarity shown in B, the
negative DUT terminal is connected to CURRENT OUTPUT HI, and the positive termi-
nals is connected to CURRENT OUTPUT LO.
Figure 3-2
Laser diode current source polarity
Current Output HI
Current Output LO
Current
Source
A. Positive Polarity
+
–
Current Output HI
Current Output LO
Current
Source
B. Negative Polarity
+
Laser
Diode
–
Laser
Diode
Optional
Earth Ground
Optional
Earth Ground
Summary of Contents for 2520
Page 250: ...A Specifications ...
Page 254: ...B StatusandErrorMessages ...
Page 262: ...C DataFlow ...
Page 266: ...D IEEE 488BusOverview ...
Page 281: ...E IEEE 488andSCPI ConformanceInformation ...
Page 285: ...F MeasurementConsiderations ...
Page 308: ...G GPIB488 1Protocol ...
Page 312: ...H ExamplePrograms ...
Page 317: ...I ContinuousPulseMode ...