Agilent Technologies 6625A - Manual (Page 57)

Output Connections and Operating Information 57
Figure 4-11. Parallel Connections with Local Sensing
CV Operation
For CV operation, one output must operate in CC mode and the other output must operate in CV mode. Although each
output operates independently of the other, the output that is operating in CV mode will be ’’controlling" the voltage
regulation of both outputs. Setting the output voltages as outlined in the following paragraph and configuring the outputs as
shown in Figure 4-11 will allow output 1 to operate in CV mode and output 2 to operate in CC mode.
To assure that output 2 will be operating in CC mode, you must program output 2’s voltage to a higher value than the
voltage of output 1. One way to accomplish this is to first program output 2 to the maximum allowable voltage setting for
the desired operating range (see Table 4-2 or Figure 4-2). These values are 1% higher than the rated voltage for the
operating range. Then, program output 1’s voltage to the desired operating voltage. The lower voltage setting of output 1
will determine the voltage that appears across the load. The current limit point of the paralleled outputs is the sum of both
individual current limit points. The output current of the parallel combination is the algebraic sum of the individual current
readbacks.
The + OV and - OV terminals of output 1 should be wired to the + OV and - OV terminals of output 2. When programming
the overvoltage setpoint, set both outputs to the same overvoltage value. When resetting the overvoltage, first disable both
outputs by using the OUTPUT ON/OFF key or OUT command. Next, reset both overvoltages. Finally, re-enable the
outputs with the OUTPUT ON/OFF key or OUT command.
Table 4-2. Maximum Allowable Voltage Setting
Output Type Maximum Low Range Voltage Maximum High Range Voltage
25W 7.07V 50.5V
50W 16.16V 50.5V
Note Below 4 V on 25 W outputs and 2 V on 50 W outputs, the downprogrammer cannot sink the maximum
rated current. (See Figures 4-2 and 4-3). To operate parallel outputs at voltages under 2.5 V, program
both outputs to the same voltage setting. Depending on the load, one output may operate in the
unregulated mode.