DP83822I: Crosstalk and Eye Diagram

Hi Brian,

Brian Wang0928 said:

Customer is using DP83822s as PHY for EtherCAT in ac inverter application. However, they're going to evaluate and measure the Near end crosstalk (NEXT), Far end crosstalk(FEXT), and also eye diagram on real motor system. 

Why are these tests needed for EtherCAT ? My understanding is these tests are needed for cables and not the PHY, is my understanding correct ?

Here is a document that will talk about how to perform DP83822 compliance tests:
https://www.ti.com/lit/an/snla266/snla266.pdf?ts=1690396295861&ref_url=https%253A%252F%252Fwww.google.com%252F

Regards,
Rahul

Thanks. 

The portacle of the motor driver could be for Ethernet and Ethercat standard.  

RD is now likely to evaluate the motor driver board without ethernet cable. RD thinks that the layout or routing of PHY would also impact the crosstalk and eye diagram performance. i know it would be very minor compared to with long cable. 

However, could you offer below info. to assistant customer! 

1. Layout guide for better immunity and crosstalk improvement. 

2. To offer the specification of the eye diagram. for exampl Tr, Tf, voltage...etc as the below diagram shown.

Regards

Brian