If manual mode is selected, you have to manually change the AC source voltage and DC load current: a window
will pop-up each time an action is necessary.
The
is able to detect when the AC source is switched on/off, which limits the interactions.
Figure 39.
Manual mode: AC source voltage and DC load current selection
See
Figure 40. NVM parameters: RAM and NVM values
for NVM options.
As NVM storage space is limited, some PFC parameters have to be uploaded with a lower resolution than NVM
values. To make sure the calibration reflects the real mode of operation, the calibrated values can be rounded to
the closest one ticking the
Use NVM parameters
check box.
The
Read NVM
button transfers the content of the chip NVM memory to the GUI. This is useful to revert to the
original calibration stored in the NVM, if the current calibration is not satisfactory.
The
Write NVM
button is used to write the current calibration in the chip NVM memory.
Figure 40.
NVM parameters: RAM and NVM values
11.4.3
Step 1: THD improver
The first step is to calibrate the THD improver since the two parameters directly affect the output power reported.
This feature helps to improve the AC current total harmonic distortion (THD) and the power factor (PF) value.
After pressing the
Reset PSU
button, follow the instructions.
Once PSU has started, you can tune the IBase and IGain settings.
There is only one possible setting, so you have to try various loads and AC voltages to find the best trade off
across all modes of operation.
UM2342
Step by step calibration example
UM2342
-
Rev 1
page 34/57
