Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
nINT not available in this
configuration
MAC
RMII
LAN8720
10/100 PHY
24-QFN
MDIO
MDC
Capable of
accepting 50MHz
clock
TXD[1:0]
RMII
2
2
TXEN
Mag
RJ45
RXD[1:0]
TXP
TXN
CRS_DV
RXER
RXP
RXN
REF_CLK
REFCLKO
XTAL1/CLKIN
XTAL2
LED[2:1]
nRST
25MHz
2
Interface
Figure 4.5 LAN8720 sources REF_CLK from a 25MHz crystal
In some system architectures, a 25MHz clock source is available. The LAN8720 can be used to
generate the REF_CLK to the MAC as shown in Figure 4.6. It is important to note that in this specific
Revision 1.0 (05-28-09)
SMSC LAN8720/LAN8720i
DATA2S8HEET