THERMAL  MANAGEMENT FOR TOTAL- ACEXTREME 
 
 
Data Device Corporation    DS-BU-67301B-G 
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∆T = (0.7-P
B
)*(24.5) = P
B
*(46.9) 
22.05-24.5 *P
B
 = 46.9*P
B
 
22.05 = 71.4*P
B
 
P
B
 = 0.3088 
Substituting this result back into the ∆T equation, we get: 
∆T = 0.2999*26.5 = 14.48°C 
So as long as both the top and bottom of the case are maintained below 120°C, 
using heat sinks if necessary, the junction temperatures will remain within the 
acceptable limits. 
The method described so far provides a conservative estimate of the acceptable 
operating temperature for a given application.  It is possible to obtain a more accurate 
estimate of the acceptable operating temperature by performing a more accurate 
simulation of the heat flows in the system.  This could potentially allow operation at 
higher ambient temperatures and duty cycles with less expensive heat removal 
methods.  To this end, DDC provides a thermal model that can be use with the 
FloTherm modeling tool from Mentor Graphics to assign power dissipation numbers 
to each internal component and determine the resulting operating junction 
temperature of each, allowing the assurance of proper operation without requiring 
excessively conservative estimates that can hurt performance and increase costs.