36
Intel
®
Celeron
®
D Processor in the 775-Land LGA Package
Thermal Design Guide
Order #303730
Conclusion
6.0
Conclusion
As the complexities of today’s microprocessors increase, power dissipation requirements become
more exacting. Care must be taken to ensure that the additional power is properly dissipated. Heat
can be dissipated using passive heatsinks, fans and/or active cooling devices. Incorporating ducted
airflow solutions into the system thermal design can yield additional margin.
The Intel Celeron D Processor in the 775-Land LGA Package integrates thermal management logic
onto the processor silicon. The Thermal Monitor feature attempts to control the processor
temperature in the event of a thermal excursion beyond the processor heatsink capability. If the die
temperature reaches the factory-calibrated temperature, the Thermal Monitor will take steps to
reduce power consumption, causing the processor to cool down. Thermal Monitor cannot
compensate for a thermal solution that does not meet the thermal profile and TDP. The use of the
on-die thermal diode in an active fan speed control solution can provide acoustic benefits and
maintain the processor thermal specification. Various registers and bus signals are available to
monitor and control the processor thermal status.
A thermal solution designed to the thermal profile at the thermal design power (TDP), as specified
in the processor datasheet, can adequately cool the processor to a level where activation of the
Thermal Monitor feature is either very rare or non-existent. Automatic thermal management must
be used as part of the total system thermal solution.
The size and type of the heatsink, as well as the output of the fan can be varied to balance size, cost,
and space constraints with acoustic noise. This document has presented the conditions and
requirements for designing a heatsink solution for a system based on a Celeron D processor in the
775-land LGA package. Properly designed solutions provide adequate cooling to maintain the
processor thermal specification. This is accomplished by providing a low local ambient
temperature and creating a minimal thermal resistance to that local ambient temperature. Fan
heatsinks or passive heatsinks with ducted airflow can be used to cool the processor if proper
package temperatures cannot be maintained otherwise. By maintaining the processor case
temperature at the values specified in the processor datasheet, a system designer can be confident
of proper functionality and reliability of these processors.