Ethernet Lines and Jack/Magnetics Data

Mag. conn., #1

RX+

Input

Ethernet port, positive line of the differential input signal pair

Mag. conn., #2

RX-

Input

Ethernet port, negative line of the differential input signal pair

Mag. conn., #9

TX+

Output

Ethernet port, positive line of the differential output signal pair

Mag. conn., #10

TX-

Output

Ethernet port, negative line of the differential output signal pair

Mag. conn., #11

AVCC

Output

"Clean" 3.3V power output for magnetics circuitry

em203a_ether

Ethernet port of the EM203A is of 100/10BaseT type. Onboard electronics of the EM203A do not include Ethernet magnetics, so magnetics circuitry must be connected externally to pins TX+, TX-, RX+, RX-, and AVCC. The AVCC pin outputs clean power for the magnetics circuitry, which is very sensitive to noise. The voltage on the AVCC output is 3.3V.

note_warning-wt

Do not interconnect the AVCC and VCC pins! This will permanently damage the EM203A.

One of the options for implementing the Ethernet front-end is to use RJ203 jack/magnetics module.