Specifications

Down Programming
Question: What is down programming?
Answer: When a power supply with current sink capability is programmed to a voltage level less than that actually
at the output terminals it will automatically begin to sink current. The downprogrammer can be thought of as an
internal load across the power supply's output terminals that helps bring the output voltage down quickly.
This is particularly useful in automated test of a device at several voltage or current levels, or in high volume testing.
The primary function of the down programmer is to discharge the power supply's output capacitor but in some cases
this feature may be used as a load to the device under test. The supply might be used to both charge and discharge a
device such as a capacitor or a battery.
Supplies vary in the level and other characteristics of current they sink. Some supplies such as the 603xA, 664xA and
665xA sink a fixed current equal to about 10% of their rated output current while the 667xA series sink a constant
power (as the output voltage falls the supply sinks more current). The 662xA series have fixed dual range sink
capability similar to their output ranges and the 663xA/B series supplies are programmable. See the Operating
manuals to determine the characteristics of each model.