Ethernet Port Lines

#6

TX+

Output

Positive line of the differential output signal pair

#7

TX-

Output

Negative line of the differential output signal pair

#3

RX+

Input

Positive line of the differential input signal pair

#4

RX-

Input

Negative line of the differential input signal pair

#5

3.3Vout

Output

"Clean" 3.3V power for magnetics circuitry

Ethernet port of the EM200 is of 100BaseT type. Onboard electronics of the EM200 do not include Ethernet magnetics, so magnetic circuitry must be connected externally. You can use either a standalone magnetics part (such as YCL-PH163112) or RJ45 connector with integrated magnetics (for example, YCL-PTC1111-01G). Diagrams below show circuit diagrams for both parts.

Please, note the following:

•The 3.3Vout is an output that provides clean power for the magnetics circuitry, which is very sensitive to noise.
•Do not combine 3.3Vout with the VCC (main power) pin. This is counter-productive and will cause FCC/CE certification issues.

em200_ether_arrangement

em200_ether_arrangement2

It is important to make the PCB wire connections between the Ethernet port pins of the EM200 and external magnetics circuitry as short as possible. Making the wires too long may cause the noise level generated by your PCB surpass the maximum radiated emission limits stipulated by FCC and CE regulations. Additionally, longer Ethernet lines on the PCB will make your board more susceptible to the damage from the ESD (electrostatic discharge).