User manual

4-2 Sweeps Model 6220/6221 User’s Manual
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Sweep overview
As shown in Figure 4-1, the Model 622x Current Source can generate three types
of DC current sweeps.
Linear staircase sweep
With this sweep type, the current increases or decreases in specific steps, begin-
ning with a start current and ending with a stop current. Figure 4-1A shows an
increasing linear staircase sweep from a 1mA start current to a 5mA stop current
in 1mA steps. The bias current is the fixed current setting just prior to the start of
the sweep. The current output will remain at the last point in the sweep after com-
pletion.
Logarithmic staircase sweep
In this case, the current increases or decreases logarithmically, beginning with a
start current and ending with a stop current. Figure 4-1B shows an increasing log
staircase sweep from a 0.1mA start current to a 100mA stop current with logarith-
mic steps. Again, the bias current is the fixed current setting just prior to the start
of the sweep. The current output will remain at the last point in the sweep after
completion.
Custom sweep
The custom sweep allows you to program arbitrary sweep steps anywhere within
the output current range of the Model 622x. Figure 4-1C shows a typical custom
sweep with arbitrary steps. As with the other two sweep types, the bias current is
the fixed current setting just prior to the start of the sweep. The current output will
remain at the last point in the sweep after completion.
NOTE User setups cannot be saved or recalled while a sweep is
armed or running. Attempting to do so will generate error
+413 Not allowed with mode arm.
NOTE A custom sweep cannot be saved as a user setup.
Attempting to do so will generate error +528 Cannot save
CUSTOM sweep setup.