LAN9221_12 Datasheet, PDF (21/151 Pages) SMSC Corporation – High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O

High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O
Datasheet
2.2
External Pull-Up/Pull-Down Resistors
As detailed in Table 2.6, when using an external pull-up or pull-down resistor, the required value is
dependant on the operating voltage. Usage of recommended pull-up/pull-down resistor values is
required to ensure proper operation.
Table 2.6 External Pull-Up/Pull-Down Resistor Values
I/O VOLTAGE
3.3V +/- 300mV
2.5 +/- 10%
1.8V +/- 10%
PULL-UP/PULL-DOWN RESISTOR VALUE (OHMS)
10K
7.5K
4.7K
2.3
Buffer Types
TYPE
VIS
VO12
VOD12
VO8
VOD8
PU
PD
AI
AO
AIO
ICLK
OCLK
Table 2.7 Buffer Types
Variable voltage input pin
DESCRIPTION
Variable voltage output with 12mA sink and 12mA source (Note 2.1)
Variable voltage open-drain output with 12mA sink (Note 2.1)
Variable voltage output 8mA symmetrical drive (Note 2.1)
Variable voltage open-drain output with 8 mA sink (Note 2.1)
50uA (typical) internal pull-up (Note 2.2)
50uA (typical) internal pull-down (Note 2.2)
Analog input
Analog output
Analog bi-directional
Crystal oscillator input pin
Crystal oscillator output pin
Note 2.1 Sink and source capabilities are dependant on the VDDVARIO voltage. Refer to Section
7.6, "DC Electrical Specifications" for additional information.
Note 2.2
When operating at reduced VDDVARIO voltage levels (less than 3.0V), do not rely on
internal pull-up and pull-down resistors to determine signal state. Refer to Section 2.2,
"External Pull-Up/Pull-Down Resistors" and the individual signal descriptions in Section
2.1, "Pin List" for more information.
SMSC LAN9221/LAN9221i
21
DATASHEET
Revision 2.9 (03-01-12)