LAN83C180 Datasheet, PDF (7/10 Pages) SMSC Corporation – 10/100 FAST ETHERNET PHY TRANSCEIVER

Migrating from the LAN83C180 10/100 PHY to the LAN83C185 10/100 PHY
4.3.2
Receive Terminations
Each of the LAN83C185 receive signals (RXP, RXN) should be AC-coupled to the magnetics module’s
receive interface via a capacitor. Additionally, RXP and RXN signals should be terminated through a resistor
via a capacitor connected to ground (see Figure 4.2 below). Please refer to the LAN83C185 Customer
Reference Board schematic for recommended values.
RXP
LAN83C185
RXN
R1_TERM
R2_TERM
C1_{AC Couple}
C2_{AC Couple}
C 3 _{AC -G N D}
Magnetics Module
Receive Channel
RD+
RCT
RD-
RX+
RCMT
RX-
Figure 4.2 - Rx to Magnetics Interface
SMSC AN 10.13
Page 7
APPLICATION NOTE
Revision 1.2 (07-12-04)