DP83822H: Parameters affect waveform shape

Hi Koike-san,

We do not recommend to touch these registers for typical operation of the device. Is there a reason why you want to modify these registers?

Best,

J

Hi J,

Thank you for replying again.
Our application is a specific use case, only for short PCBs communication.
The requirements for board size is very strict.
So, I have to try deleting pulse transformers.
When degrading transmission quality without pulse transformers.
I'd like to adjust the parameters for recovering.
That's why.

Hi Koike-san,

For transformerless operation, you can refer to this document:

 [FAQ] TI Ethernet PHY Capacitive Coupling (Transformerless Operation)

For DP83822, you can put 33nF decoupling capcitors for transformerless operation and it should work without the need to adjust the registers you mentioned.

If there are any issues, then I would suggest to start tuning the registers. However, our expectation of the PHY is that it will work without transformers and board to board connection via PCB trace.

Best,

J