Hello ,
for one ur Product i used MP8009GV . I used Figure 20 on Page 36 for ur Board .At first AUX did not work, then i remove R34 ( i saw here) ,then it’s ok. But POE+ (802.3at) doesn’t work at all . I tried to see in OSCI , between VDD and VSS , then it worked. I found when i Connected VSS to ETH of OSCI
then it works . I think the problem comes from Rdet , i have changed it but , same issue .
Could you pls help me ?
Hi pouria,
You should set Rdet to 24.9kΩ (±1%). I would recommend leaving as is. The valid signature
resistance detected on the power interface (PI) is between 23.7kΩ and 26.3kΩ.
Just to clarify, you are seeing full functionality when removing R34 and connecting VSS to ETH on the oscilloscope?
Could you share your schematic?
I find it helpful to reference our evaluation boards as they are optimized to operate under the conditions outlined in its respective datasheet. Here you can compare your schematic to what MPS can guarantee is operational. This can help debug or show any glaring differences in the applications.
Hi again , Yes i will share it . I did it as datasheet . I did not remove at all Rdet and it’s 24.9K.
when i connect VSS (-VPOE) to Ground of OSCI , then it works .