User`s guide

6 Advanced Source and Measurement Functions
154 Model N6705 User’s Guide
Source Operating Modes
Single Quadrant Operation
The DC Power Analyzer can operate in either constant voltage (CV)
or constant current (CC) over the rated output voltage and current.
Constant voltage mode is defined as an operating mode in which the
dc source maintains its output voltage at the programmed voltage
setting in spite of changes in load, line, or temperature. Thus, when
the load resistance changes, the output voltage remains constant
while the output current changes to accommodate the change in load.
Constant current mode is defined as an operating mode in which the
dc source maintains its output current at the programmed current
limit in spite of changes in load, line, or temperature. Thus, when the
load resistance changes, the output current remains constant while
the output voltage changes to accommodate the change in load.
All DC power modules, except for Agilent Models N678xA SMU,
are designed as constant voltage sources. This means that the
specifications and operating characteristics are optimized for
constant voltage mode operation. Note that these power modules
cannot be programmed to operate in a specific mode. At turn-on, the
operating mode will be determined by the voltage setting, current
setting, and the load resistance. In the following figure, operating
point 1 is defined by a fixed load line traversing the positive
operating quadrant in the constant voltage region. Operating point 2
is defined by a fixed load line traversing the positive operating
quadrant in the constant current region.
Voltage
Current
Iset
Vset
C
C
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0
1
2
Vmax
Imax
M
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C
V
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Less load resistance
More load
resistance
Downprogrammer
characteristic