DDC Total-AceXtreme MIL-STD-1553 Design Manual page 115

T H E R M A L M A N A G E M E N T F O R T O T A L - A C E X T R E M E
Substituting this result back into the ∆T equation, we get:
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.
Data Device Corporation
www.ddc-web.com
∆T = (0.7-P
)*(24.5) = P
B
22.05-24.5 *P = 46.9*P
B
22.05 = 71.4*P
P = 0.3088
B
∆T = 0.2999*26.5 = 14.48°C
106
*(46.9)
B
B
B
DS-BU-67301B-G
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