Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
Table 2.6 Analog Reference Pins
BUFFER
TYPE
NUM PINS
NAME
SYMBOL
DESCRIPTION
External 1%
Bias Resistor
Input
RBIAS
AI
This pin requires connection of a 12.1k ohm (1%)
resistor to ground.
Refer to the LAN8720A/LAN8720Ai reference
schematic for connection information.
1
Note:
The nominal voltage is 1.2V and the
resistor will dissipate approximately
1mW of power.
Table 2.7 Power Pins
BUFFER
TYPE
NUM PINS
NAME
SYMBOL
DESCRIPTION
+1.6V to
+3.6V
Variable I/O
Power
VDDIO
P
+1.6V to +3.6V variable I/O power
1
Refer to the LAN8720A/LAN8720Ai reference
schematic for connection information.
+1.2V Digital
Core Power
Supply
VDDCR
P
Supplied by the on-chip regulator unless
configured for regulator off mode via the
REGOFF configuration strap.
Refer to the LAN8720A/LAN8720Ai reference
schematic for connection information.
1
1
Note:
1 uF and 470 pF decoupling capacitors
in parallel to ground should be used on
this pin.
+3.3V
Channel 1
Analog Port
Power
VDD1A
VDD2A
P
P
+3.3V Analog Port Power to Channel 1
Refer to the LAN8720A/LAN8720Ai reference
schematic for connection information.
+3.3V
Channel 2
Analog Port
Power
+3.3V Analog Port Power to Channel 2 and the
internal regulator.
1
1
Refer to the LAN8720A/LAN8720Ai reference
schematic for connection information.
Ground
VSS
P
Common ground. This exposed pad must be
connected to the ground plane with a via array.
Revision 1.4 (08-23-12)
14
SMSC LAN8720A/LAN8720Ai
DATASHEET