Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
10/100
Ethernet
MAC
RMII
LAN8720A/
LAN8720Ai
MDI
Transformer
RJ45
Mode
LED
Crystal or
Clock
Oscillator
Figure 1.1 System Block Diagram
MODE[0:2]
nRST
RMIISEL
Mode Control
Reset Control
Auto-
Negotiation
100M TX
Logic
100M
Transmitter
HP Auto-MDIX
TXP/TXN
RXP/RXN
Transmitter
SMI
TXD[0:1]
TXEN
Management
Control
10M TX
Logic
10M
Transmitter
MDIX
Control
XTAL1/CLKIN
PLL
RXD[0:1]
XTAL2
RMII Logic
RXER
100M RX
Logic
DSP System:
Clock
Data Recovery
Equalizer
Analog-to-
Digital
100M PLL
Interrupt
Generator
LEDs
nINT
CRS_DV
MDC
MDIO
LED1
LED2
Receiver
10M RX
Logic
10M PLL
Squeltch
& Filters
Central Bias
PHY Address
Latches
RBIAS
PHYAD0
LAN8720A/LAN8720Ai
Figure 1.2 Architectural Overview
Revision 1.4 (08-23-12)
8
SMSC LAN8720A/LAN8720Ai
DATASHEET
SMSC [ SMSC CORPORATION ]
