Toradex Apalis Series - 2.4 Ethernet

Apalis Carrier Board Design Guide
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2.3.3 Unused SATA Signals Termination
Apalis
Pin
Apalis
Signal Name
Recommended Termination
33
SATA1_TX+
Leave NC if not used
31
SATA1_TX-
Leave NC if not used
25
SATA1_RX+
Preferable connect to GND if not used or leave NC
27
SATA1_RX-
Preferable connect to GND if not used or leave NC
35
SATA1_ACT#
Leave NC if not used
Table 6: Unused SATA signal termination
2.4 Ethernet
The Apalis module standard features a single Gigabit Ethernet (1000Base-T) interface port. The
interface is backward compatible with the 10/100Mbit Ethernet (10/100Base-TX) standard. Some
Apalis modules may feature only 10/100Base-TX instead of 1000Base-T. Please consult the
relevant datasheet of the module for more information about the interface speed.
2.4.1 Ethernet Signals
Apalis
Pin
Apalis
Signal Name
I/O
Type
Power
Rail
Description
50
ETH1_MDI0+
I/O
Analogue
1000Base-T: DA+
10/100Base-TX: Transmit +
48
ETH1_MDI0-
I/O
Analogue
1000Base-T: DA-
10/100Base -TX: Transmit -
56
ETH1_MDI1+
I/O
Analogue
1000Base-T: DB+
10/100Base -TX: Receive +
54
ETH1_MDI1-
I/O
Analogue
1000Base-T: DB-
10/100Base -TX: Receive -
32
ETH1_MDI2+
I/O
Analogue
1000Base-T: DC+
10/100Base -TX: Unused
34
ETH1_MDI2-
I/O
Analogue
1000Base-T: DC-
10/100Base -TX: Unused
38
ETH1_MDI3+
I/O
Analogue
1000Base-T: DD+
10/100Base -TX: Unused
40
ETH1_MDI3-
I/O
Analogue
1000Base-T: DD-
10/100Base -TX: Unused
46
ETH+_CTREF
O
Analogue
Centre tap supply
42
ETH1_ACT
O
CMOS
3.3V
LED indication output for activity on the Ethernet port
44
ETH1_LINK
O
CMOS
3.3V
LED indication output for established Ethernet link
Table 7: Ethernet signals
2.4.2 Reference Schematics
Ethernet connectors with integrated magnetics are preferable. If a design with external magnetics
is chosen, additional care has to be taken to route the signals between the magnetics and Ethernet
connector. If only a fast Ethernet (100Mbit/s) is required, some design costs may be saved by using
only 10/100Base-TX magnetics.
The magnetics provide a certain ESD protection which is sufficient for many designs. However,
especially in Power over Ethernet (PoE) systems, additional transient voltage suppressor diodes
(TVS) are highly recommended to be placed between the module and the magnetics. More
information can be found in the following application note from Microchip:
http://ww1.microchip.com/downloads/en/AppNotes/00002157B.pdf
The LED output signals ETH1_ACT and ETH1_LINK can be connected directly to the LED of the
Ethernet jack with suitable serial resistors. There is no need for additional buffering if the current