Networking Silicon — 82540EP
Datasheet
29
5.3
Thermal Specifications
The 82540EP device is specified for operation when the ambient temperature (TA) is within the
range of 0
°
C to 70
°
C.
TC (case temperature) is calculated using the equation:
TC = TA + P (
θ
JA - q JC)
TJ (junction temperature) is calculated using the equation:
TJ = TA + P
θ
JA
P (power consumption) is calculated by using the typical ICC, as indicated in
Table 4 of Section 4.0
,
and nominal VCC. The thermal resistances are shown in
Table 18
.
Thermal resistances are determined empirically with test devices mounted on standard thermal test
boards. Real system designs may have different characteristics due to board thickness, arrangement
of ground planes, and proximity of other components. The case temperature measurements should
be used to assure that the 82540EP device is operating under recommended conditions.
Table 18. Thermal Characteristics
Symbol
Parameter
Value at specified airflow (m/s)
Units
0
1
2
3
θ
JA
Thermal resistance, junction-to-ambient
28.1
25.0
23.7
22.8
°C/
Watt
θ
JC
Thermal resistance, junction-to-case
6.1
6.1
6.1
6.1
°C/
Watt
