GD82551ER Intel, GD82551ER Datasheet - Page 20

• Manufacturer Part Number: GD82551ER
• Manufacturer: Intel

Specifications of GD82551ER

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 196
• Lead Free Status / RoHS Status: Not Compliant

82551ER — Networking Silicon
4.5
12
Table 8.
PHY Signals
PHY Signals
a. Based on some board designs, RBIAS100 and RBIAS10 values may need to be increased/decreased to com-
X1
X2
TDP
TDN
RDP
RDN
ACTLED#
LILED#
SPEEDLED#
RBIAS100
RBIAS10
VREF
pensate for high/low MDI transmit amplitude. See the 82562EZ(EX)/82551ER(IT) & 82541ER Combined Foot-
print LOM Design Guide for more information.
Symbol
AI
AO
AO
AI
OUT
OUT
OUT
B
B
B
Type
Crystal Input One. X1 and X2 can be driven by an external 25 MHz
crystal. Otherwise, X1 may be driven by an external 3.3 V metal-oxide
semiconductor (MOS) level 25 MHz oscillator when X2 is left floating.
Crystal Input Two. X1 and X2 can be driven by an external 25 MHz
crystal. Otherwise, X1 may be driven by an external 3.3 V MOS level
25 MHz oscillator when X2 is left floating.
Analog Twisted Pair Ethernet Transmit Differential Pair. These
pins transmit the serial bit stream for transmission on the Unshielded
Twisted Pair (UTP) cable. The current-driven differential driver can be
two-level (10BASE-T) or three-level (100BASE-TX) signals depending
on the mode of operation. These signals interface directly with an
isolation transformer.
Analog Twisted Pair Ethernet Receive Differential Pair. These pins
receive the serial bit stream from the isolation transformer. The bit
stream can be two-level (10BASE-T) or three-level (100BASE-TX)
signals depending on the mode of operation.
Activity LED. The Activity LED pin indicates either transmit or receive
activity. When activity is present, the activity LED is on (ACTLED#
active low); when no activity is present, the activity LED is off.
Link Integrity LED. The Link Integrity LED pin indicates link integrity.
If the link is valid in either 10 or 100 Mbps, the LED is on (LILED#
active low); if link is invalid, the LED is off.
Speed LED. The Speed LED pin indicates the speed. The speed LED
will be on at 100 Mbps (SPEEDLED# active low) and off at 10 Mbps.
Reference Bias Resistor (100 Mbps). This pin should be connected
to a pull-down resistor.
Reference Bias Resistor (10 Mbps). This pin should be connected
to a pull-down resistor.
Voltage Reference. This pin is connected to a 1.25 V ± 1% external
voltage reference generator. To use the internal voltage reference
source, this pin should be left floating. Under normal circumstances,
the internal voltage reference should be used and this pin would be left
open.
a
a
Name and Function
Datasheet