Hi,
we are having problems getting the below schematic to work robustly.
The idea is to have a PoE-PD and divert the 48-56VDC from the PoE switch to a remote sink. So for 802.3at app. 2-3W would be fed into the flyback and converted down to 12V for local supply. The remaining power would be fed from the PoE rail (48-56VDC) via the eFuse to a remote sink.
We were hoping the eFuse would switch on only after the PoE switch is supplying the full voltage and also provide power in a controlled way. However, we have already destroyed 3 pieces of TPS26621 just by connecting the load to the output. The destroyed ICs all show an internal closed circuit. Have we overlooked something in the application design?
Best regards,
Michael
