SNLA056A design guide written in below points of "Twisted Pair Interface" section (page 10).
・MDI pair is the each cable length and 50Ω inpedance
・Do not use bia and stabs
・Do not cross the line
But in reality, MDI pair will cross the "+" and "-" line because of DP83865 pin assign.
Please see below.
※MDIA→Trans TD4→Trans MX4→RJ-45[A]
MDIB→Trans TD3→Trans MX3→RJ-45[B]
MDIC→Trans TD2→Trans MX2→RJ-45[C]
MDID→Trans TD1→Trans MX1→RJ-45[D]
①Question-1
Is there reference circuit of clear line (No bia and no cross line)?
Or, is there any idea?
②Question-2
I think that below pattern (reverse the "+" and "-" line) is clear, is it no problem?
※MDIA[+]→Trans TD4[-]→Trans MX4[-]→RJ-45[A+]
MDIA[-]→Trans TD4[+]→Trans MX4[+]→RJ-45[A-]
MDIB[+]→Trans TD3[-]→Trans MX3[-]→RJ-45[B+]
MDIB[-]→Trans TD3[+]→Trans MX3[+]→RJ-45[B-]
MDIC[+]→Trans TD2[-]→Trans MX2[-]→RJ-45[C+]
MDIC[-]→Trans TD2[+]→Trans MX2[+]→RJ-45[C-]
MDID[+]→Trans TD1[-]→Trans MX1[-]→RJ-45[D+]
MDID[-]→Trans TD1[+]→Trans MX1[+]→RJ-45[D-]
Best regards,
Satoshi
