I am using TJ1410A on a custom board. I am evaluating mac to work with this PMD chip. When data is sent to this PMD chip on differential wire, it then sends the data frame to MAC on 3-wire RX (RX with respect to mac). The VCC provided to TJ1410 chip is 3.3 V and I see some activity on RX (which was high at 3.3V). Now the activity fluctuates from 3.2 V to 2V (instead of 3.3 to 0V). So the mac sees this as RX high and thinks that it is silent. Why is the voltage swing not correct (attaching a scope capture screenshot). Also do you have a datasheet on this part (TJ1410) - please share.
Hello bitmasker
Good day!
Could you verify your VIO pin connection, confirm VIO is connected to your supply. The TJA1410A supports 1.8 V to 3.3 V on VIO. If you are supplying 3.3 V on VCC but VIO is left open or unconnected, the RX output cannot swing to ground.
You can find the datasheet on our official website TJA1410 under the "Documentation > Secure" section.
Unfortunately, it is a confidential file, so you must have an NDA in place with us to access it. I recommend opening a support ticket stating that you wish to sign an NDA so that your request can be routed to the appropriate team.
I hope this information has helped you, please let me know if you need help with anything else.
Have a great day and best of luck.