Is the fpc something else than a typical 1:1? Maybe it is my old eyes but CM4 signal TRD0_P pin 12 goes to FPC2 connector pin 2. On the connector board the same signal is pin 5 in the FPC1 connector. Looks like signals are shifted by 3 pins and also TRD1 polarity is swapped.
There are some other considerations as well. Here are first that got my attention:
* looks like lan pairs are not matched
* avoid stubs
* from pin to GND via as short as possible and do not continue to another pin
* there are several ground return paths on the the upper CM4 connector (partially the same as the above)
* on the connector board bring signal pairs closer together near rj connector
* looks there is unused trace between TRD signals on the connector board. Or two on both sides...
There are some other considerations as well. Here are first that got my attention:
* looks like lan pairs are not matched
* avoid stubs
* from pin to GND via as short as possible and do not continue to another pin
* there are several ground return paths on the the upper CM4 connector (partially the same as the above)
* on the connector board bring signal pairs closer together near rj connector
* looks there is unused trace between TRD signals on the connector board. Or two on both sides...
Statistics: Posted by gotaf80307 — Fri May 10, 2024 3:48 pm
