Hello.
We've been using the UCC28C43DR regulator on our boards since many years. Now we have received the first reels of this component according to PCN# 20221216002.1
According to the PCN there should be no functional impact, but we noticed some differences, if we compare to the previous version of the component (before the PCN). These differences are not explained in the datasheet.
Furthermore, in the PCN we noticed that ‘Design change’ is selected.
Could you please explain in detail which are the differences from the old UCC28C43DR (prior to PCN) to the new UCC28C43DR (after PCN)?
Comparing the waveforms, the new UCC28C43DR switches off much more quickly.
With no load, the old UCC28C43DR works in burst-mode. The new UCC28C43DR is always switching.
Due to this, the input current of our converter (with no load) is more than double, using the new UCC28C43DR.
This test was made on the same board, with exactly the same components, only the regulator was replaced from old version to new version.
Pic01: drain of switching FET (flyback-stage)
White trace: old UCC28C43DR
Yellow trace: new UCC28C43DR
Attachment Pic02: drain of switching FET (flyback-stage), old UCC28C43DR, no load
Attachment Pic03: drain of switching FET (flyback-stage), new UCC28C43DR, no load
Thank you.