Thermal Considerations
VL-EPU-4012 Hardware Reference Manual
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Thermal Considerations
This chapter discusses the following topics related to thermal issues:
Selecting the correct thermal solution for your application
EPU-4012 thermal characterization
Installing the passive (HDW-416 heat sink), the active (HDW-415 fan), and the heat pipe
block (HDW-408) thermal solutions available from VersaLogic
Selecting the Correct Thermal Solution for Your Application
This section provides guidelines for the overall system thermal engineering effort.
Heat Plate
The heat plate supplied with the Owl is the basis of the thermal solution. The heat plate draws
heat away from the CPU chip as well as other critical components. Some components rely on the
ambient air temperature at or below the maximum specified 85 ºC temperature.
The design of the heat plate assumes that the user’s thermal solution will maintain the top surface
of the heat plate at 90 ºC or less. If that temperature threshold is maintained, the CPU will remain
safely within its operating temperature limits.
CAUTION:
By itself, the heat plate is not a complete thermal solution. Integrators should either implement a
thermal solution using the accessories available from VersaLogic or develop their own thermal
solution that attaches to the heat plate, suitable for environments in which the EPU-4012 will be
used. As stated above, the thermal solution must be capable of keeping the top surface of the
heat place at or below 90 ºC and the air surrounding the components in the assembly at or below
85 ºC.
The heat plate is permanently affixed to the Owl and must not be removed. Removal of the heat
plate voids the product warranty. Attempting to operate the Owl without the heat plate voids the
product warranty and can damage the CPU.
System-level Considerations
The Owl is often mounted directly to another thermally controlled surface via its heat plate (that
is, the inside surface of an enclosure). In this case, the user needs to maintain the heat plate at or
below 90 ºC by controlling the mounting surface temperature. The EPU-4012 thermal solutions
available from VersaLogic – the HDW-416 heat sink with or without the HDW-415 fan, or the
HDW-408 heat pipe block – can be used in the user’s final system or only used during product
development as a temporary bench-top solution.
The ambient air surrounding the EPU-4012 needs to be maintained at 85 ºC or below. This may
prove to be challenging depending on how and where the EPU-4012 is mounted in the end user
system.
