gwixp425bdt Intel Corporation, gwixp425bdt Datasheet - Page 81

• Manufacturer Part Number: gwixp425bdt
• Description: Intel Xp42x Product Line Of Network Processors And Ixc1100 Control Plane Processor
• Manufacturer: Intel Corporation

4.3
Note:
4.3.1
4.3.2
Datasheet
Package Thermal Specifications
The thermal characterization parameter “<
between the top, center of the package and the junction temperature.
This can be a useful value for verifying device temperatures in an actual environment. By
measuring the package of the device, the junction temperature can be estimated, if the thermal
characterization parameter has been measured under similar conditions.
The use of <
junction to the external surface of the package or case nearest the die attachment — as the case is
held at a constant temperature.
The case temperature can then be monitored to make sure that the maximum junction temperature
is not violated. Examples are given in the following sections.
For more information on
Commercial Temperature
“Commercial” temperature range is defined in terms of the ambient temperature range, which is
specified as 0q C to 70q C. The maximum power (P) is 2.4 W and the maximum junction
temperature (T
<
Using the preceding junction-temperature formula, the commercial temperature for a 266 MHz
device — assuming a maximum power of 2 W — would be:
Extended Temperature
“Extended” temperature range is defined in terms of the ambient temperature range, which is
specified as -40q C to 85q C. The maximum power (P) is 2.4 W and the maximum junction
temperature (T
<
Using the preceding junction-temperature formula, the extended temperature for a 533 MHz device
— assuming a maximum power of 2.4 W — would be:
Case temperature = Junction Temperature - (
T
T
T
T
T
JT
JT
JC
JC
JC
JC
JC
Intel
for commercial temperature is 0.89° C/W.
for extended temperature is 0.32° C/W.
= T
= 115qC - (0.89 * 2.0)
= 113.22qC
= 115qC - (0.32 * 2.4)
= 114.23qC
®
J
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
- (
<
JT
JT
j
j
) is 115 q C.
) is 115q C.
should not be confused with 4
* Power Dissipation)
Document Number: 252479, Revision: 005
<
JT, refer to the EIA/JEDEC Standard 51-2, Section 4.
JT”
<
jc,
is proportional to the temperature difference
JT
which is the thermal resistance from the device
* Power Dissipation)
March 2005
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