I'm looking in the datasheet and layout guide of the DP838481 but I can't seem to find where it talks about length matching for the RX and TX differential pairs. It only mentions length matching for the MDI signals.
In this guide for 82579 Gigabit PHY chip (much faster than what my chip is operating at ~10/100 Mbps) it says to keep each differential segment within 5 mils. But in the MDI interface section it also says not to use serpentine routing!
"Do not use serpentine routing (zig zag of shorter trace) to match the trace lengths. Serpentine routing to the RJ- 45 connector which connects to long out-of-system unshielded cables can contribute to radiated EMI and can decrease immunity to ESD" Page 18 of 82579 Datasheet
How close should my differential pairs match ? And should we really not use serpentine routing for these signals ?
Thanks in advance!