Intel 200 User Manual

Thermal and Mechanical Design Guidelines 

 29 

Figure 10  illustrates the combination of the different thermal characterization 

parameters. 

     

 

 

 

The cooling performance, Ψ

JA,

 is then defined using the principle of thermal 

characterization parameter described above: 

•  The junction temperature 

TJ-MAX

 and thermal design power TDP given in the 

processor datasheet. 

•  Define the allowable heatsink temperature for processor, T

S-TOP-MAX

.   

The following provides an illustration of how one might determine the appropriate not 

related to any specific Intel processor thermal specifications, and are for illustrative 

purposes only.  

Assume the TDP, as listed in the datasheet, is 20 W and the maximum junction 

temperature 20 W is 90 °C.  Assume as well that the system airflow has been 

designed such that the local ambient temperature is 42 °C, and Ψ

HS_BASE 

= 0.3 °C/W. 

Then the following could be calculated using Equation 2: 

Ψ

JA

 = (T

J

 – T

A

) / TDP = (90 – 55) / 20 = 1.75 °C/W  

T

S-TOP

 

TIM

 

T

J 

Ψ

JS

 

Ψ

HS BASE

 

Ψ

S-TOP-A

 

T

A