82573 Datasheet, PDF (16/39 Pages) Intel Corporation – GbE Controllers

82573—Datasheet
2.8
2.8.1
2.8.2
2.9
Power Signals
Power Support Signals
Signal
CTRL_25
CTRL_12
EN25REG
Type
Name and Function
P
P
I/PU
2.5V Control
This is the voltage control signal for external 2.5V. It is only active when the
EN25REG signal is low (disabled). When external 2.5V and 1.2V supplies are used,
CTRL_25 can be left floating or can be connected to ground through a 3.3 KΩ
resistor.
1.2V Control
This is the voltage control signal for external 1.2V. When external 2.5V and 1.2V
supplies are used, CTRL_12 can be left floating or can be connected to ground
through a 3.3 KΩ resistor.
Enable 2.5V Regulator
When this signal is high, the internal 2.5V regulator is enabled. When it is low, the
internal 2.5V regulator is disables and the CTRL_25 signal is active. This signal
should be pulled up to the 3.3V power rail.
Digital and Analog Power Supply Signals
Signal
Type
Name and Function
VCC33
P
VCC25
P
VCC12
P
IREG25_IN
(82573E/V)
P
VCC3.3_REG25
(82573L only)¹
VCC25_OUT
P
3.3V Power Supply
This signal is used for I/O circuits.
2.5V Analog Power Supply
These signals are used for PHY analog, PHY I/O, PCIe* analog and phase lock loop
circuits. All 2.5V pins should be connected to a single power supply.
1.2V Digital Power Supply
These signals are used for core digital, PHY digital, PCIe* digital and clock circuits.
All 1.2V pins should be connected to a single power supply.
IREG25_IN
3.3V power supply for internal 2.5V regulator. When external 2.5V and 1.2V
supplies are used, IREG25_IN should be connected to 3.3V.
VCC25_OUT
2.5V output supply from internal power supply. When external 2.5V and 1.2V
supplies are used, VCC25_OUT can be left floating.
1. This signal is used in all three devices and has the same functionality but is denoted as IREG25_IN for the
82573E/V and VCC3.3_REG25 for the 82573L.
Grounds and No Connects
Signal
VSS
NC
Type
Name and Function
Ground
P
These signals connect to ground.
VSS is also referred to as GND.
No Connect
These pins are reserved by Intel and might have factory test functions. For normal
operation, do not connect any circuitry to these pins. Do not connect pull-up or
pull-down resistors.
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