18 of 43 November 28, 2011
IDT 89HPES48T12G2 Data Sheet
Power Consumption
Typical power is measured under the following conditions: 25°C Ambient, 35% total link usage on all ports, typical voltages defined in Table 13
(and also listed below).
Maximum power is measured under the following conditions: 70°C Ambient, 85% total link usage on all ports, maximum voltages defined in
Table 13 (and also listed below).
Note 1: I/O supply of 3.3V is preferred.
Note 2: The above power consumption assumes that all ports are functioning at Gen2 (5.0 GT/S) speeds. Power consumption can be
reduced by turning off unused ports through software or through boot EEPROM. Power savings will occur in V
DD
PEA, V
DD
PEHA, and
V
DD
PETA. Power savings can be estimated as directly proportional to the number of unused ports, since the power consumption of a turned-
off port is close to zero. For example, if 2 ports out of 12 are turned off, then the power savings for each of the above three power rails can be
calculated quite simply as 2/12 multiplied by the power consumption indicated in the above table.
Note 3: Using a port in Gen1 mode (2.5GT/S) results in approximately 18% power savings for each power rail: V
DD
PEA, V
DD
PEHA, and
V
DD
PETA.
Number of Active
Lanes per Port
Core Supply
PCIe Analog
Supply
PCIe Analog
High Supply
PCIe
Transmitter
Supply
I/O Supply Total
Typ
1.0V
Max
1.1V
Typ
1.0V
Max
1.1V
Typ
2.5V
Max
2.75V
Typ
1.0V
Max
1.1V
Typ
2.5V
Max
2.75V
Typ
Power
Max
Power
8/8/8/8/8/8
(Full Swing)
mA 3200 5336 2313 2705 816 825 845 898 24 29
Watts 3.20 5.87 2.31 2.98 2.04 2.27 0.85 0.99 0.06 0.08 8.46 12.18
8/8/8/8/8/8
(Half Swing)
mA 3200 5336 1989 2327 816 825 439 467 24 29
Watts 3.20 5.87 1.99 2.56 2.04 2.27 0.44 0.51 0.06 0.08 7.73 11.29
Table 15 PES48T12G2 Power Consumption — 2.5V I/O
Number of Active
Lanes per Port
Core Supply
PCIe Analog
Supply
PCIe Analog
High Supply
PCIe
Transmitter
Supply
I/O Supply Total
Typ
1.0V
Max
1.1V
Typ
1.0V
Max
1.1V
Typ
2.5V
Max
2.75V
Typ
1.0V
Max
1.1V
Typ
3.3V
Max
3.465V
Typ
Power
Max
Power
8/8/8/8/8/8
(Full Swing)
mA 3200 5336 2313 2705 816 825 845 898 30 35
Watts 3.20 5.87 2.31 2.98 2.04 2.27 0.85 0.99 0.10 0.12 8.50 12.22
8/8/8/8/8/8
(Half Swing)
mA 3200 5336 1989 2327 816 825 439 467 30 35
Watts 3.20 5.87 1.99 2.56 2.04 2.27 0.44 0.51 0.10 0.12 7.77 11.33
Table 16 PES48T12G2 Power Consumption — 3.3V I/O