The following PLZ models have a bias power supply inside to support 0-V input, which allow them to sink a current even if the voltage at the DC input terminal falls to 0 V.
0-V input operating voltage models:
- PLZ164WA
- PLZ664WA
- PLZ70UA
Taking PLZ164WA as an example, when the DUT (switching power supply) is turned off, the bias power supply inside PLZ164WA and the DUT will be connected in series to keep flowing a current.
The load current continues to flow into the diode at the secondary side of the DUT, so that the voltage at the DC input terminal may fall below 0 V.
Then, the reverse-connection detection raises ‘Reverse Alarm’ to turn off the load.
To prevent this, set ‘CC+CV’ or ‘CR+CV’ mode and set the +CV setting such as 0 V or 0.1 V.
With this setting, the above models will turn off the load current if the voltage drops below the set +CV value.
