Agilent Technologies Series N6700 User Manual page 123

Current Priority Mode
Series N6700 User's Guide
When the output current reaches either the positive or negative
current limit, the unit no longer operates in constant voltage mode
and the output voltage is no longer held constant. Instead, the power
supply will now regulate the output current at its current limit
setting. Either a LIM+ (positive current limit), or LIM− (negative
current limit) status flag is set to indicate that a current limit has
been reached.
As shown by the vertical portions of the load line, when the unit is
sinking power, the output voltage may continue to increase in the
positive or negative direction as more current is forced into the unit.
When the output voltage exceeds either the positive or negative over-
voltage setting, the output will shut down, the output relays will
open, and either the OV or OV- and the PROT status bits will be set.
Either the user-defined over-voltage setting or the local over-voltage
function can trip the over-voltage protection.
In current priority mode, the output current should be programmed
to the desired positive or negative value. A positive voltage limit
value should also be set. The voltage limit should always be set higher
than the actual output voltage requirement of the external load. With
tracking enabled, the negative voltage limit tracks the positive voltage
limit setting. With tracking disabled, you can set different values for
the positive and negative voltage limits.
The following figure shows the current priority operating locus of the
power modules. The area in the white quadrants shows the output as
a source (sourcing power). The area in the shaded quadrants shows
the output as a load (sinking power).
+V limit
OC
-1 A /
-3 A
− Voltage
-V limit
operation
applies to
N6784A
only
Key
Sourcing power
Sinking power
Programmable
Source Operating Modes Appendix E
+ Voltage
+20 V /
+6 V
I setting
-20 V /
-6 V
+ Current
+1 A /
+3 A
OC
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