W5500 POE and/or 4 Wire

Hi Wiznet Team,

i currently create a Test PCB with a W5500.

One Question: On the Datasheet w5500_ref_0901.pdf
Right down Corner the resistor Network 49R9 on PIN4+5 / PIN7+8

it is necessary to connect a Cable on this PIN’s or can i use a 4 Wire network cable.
and it it necessary to use the resistor network without 4 pin wire ???

please Info


It is not necessary. But, We recommend to use like our reference.
The unused pairs(4-5, 7-8) with 49.9ohms are connected to the chassis ground(CGND) with a high voltage capacitor(4.7nF/2kV). Any ESD high voltage entering on these pairs will pass to chassis ground(CGND) without damaging the circuit or the device.