Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
3.5
10/100 Line Interface Signals
Table 3.6 10/100 Line Interface Signals 24-QFN
SIGNAL
NAME
24-QFN
PIN #
TYPE
DESCRIPTION
Transmit/Receive Positive Channel 1.
TXP
TXN
RXP
RXN
21
20
23
22
AIO
AIO
AIO
AIO
Transmit/Receive Negative Channel 1.
Transmit/Receive Positive Channel 2.
Transmit/Receive Negative Channel 2.
3.6
Analog Reference
Table 3.7 Analog References 24-QFN
SIGNAL
NAME
24-QFN
PIN #
TYPE
DESCRIPTION
RBIAS
24
AI
External 1% Bias Resistor. Requires an 12.1k resistor to ground connected
as described in the Analog Layout Guidelines. The nominal voltage is 1.2V
and therefore the resistor will dissipate approximately 1mW of power.
3.7
Power Signals
Table 3.8 Power Signals 24-QFN
SIGNAL
NAME
24-QFN
PIN #
TYPE
DESCRIPTION
9
P
+1.6V to +3.6V Variable I/O Pad Power
VDDIO
VDDCR
6
P
+1.2V (Core voltage) - 1.2V for digital circuitry on chip. Supplied by the on-
chip regulator unless configured for regulator off mode using the
RXCLK/REGOFF pin. A 1uF decoupling capacitor to ground should be used
on this pin when using the internal 1.2V regulator.
VDD1A
VDD2A
VSS
19
1
P
P
+3.3V Analog Port Power to Channel 1.
+3.3V Analog Port Power to Channel 2 and to internal regulator.
FLAG
GND
The flag must be connected to the ground plane with a via array under the
exposed flag. This is the ground connection for the IC.
SMSC LAN8720/LAN8720i
Revision 1.0 (05-28-09)
DATA1S7HEET
SMSC [ SMSC CORPORATION ]
