Ethernet Port Lines

There are two different Ethernet magnetics arrangements: one for original EM1000-...-00 and another for the EM1000-...-01/-02.

The Ethernet port of the EM1000 is of the 10/100BaseT type. The onboard electronics of the EM1000 do not include Ethernet magnetics, so magnetics circuitry must be connected externally to the 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 pin depends on the EM1000 version: 3.3V for -00 and 2.5V for the -01/-02. Separate AGND analog ground pins have been added on the -01/-02 versions. For the -00 version, there is no separate analog ground. Please note the following:

You can use either a standalone magnetics part (such as YCL-PH163112) or an RJ45 connector with integrated magnetics (i.e., YCL-PTC1111-01G). Here are two connection diagrams based on the YCL-PTC1111-01G — one for the -00 and another for the -01/-02.

Once again, the -00 is a legacy part that has been replaced with the -01/-02. In case you have already made the PCB based on the -00 specifications and are not willing to change it, you can easily modify it to accommodate the -01/-02 (see diagram below):

A circuit diagram illustrating how to change a host PCB to accommodate the EM1000-...-01.

It is important to make the PCB wire connections between the Ethernet port pins of the EM1000 and external magnetics circuitry as short as possible. Making the wires too long may cause the noise level generated by your PCB to surpass the maximum radiated emission limits stipulated by FCC/CE regulations. Additionally, longer Ethernet lines on the PCB will make your board more susceptible to damage from electrostatic discharge (ESD).

The EM1000 also has two Ethernet status LED control lines.