VL-EPU-3311 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-3311 thermal characterization
Installing the passive (HDW-406 heat sink), the active (HDW-411 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 Osprey 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 being maintained at or below the maximum specified 85 ºC temperature.
The heat plate is designed with the assumption 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-3311 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 Osprey and must not be removed. Removal of the
heat plate voids the product warranty. Attempting to operate the Osprey without the heat plate
voids the product warranty and can damage the CPU.
System-level Considerations
The Osprey 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-3311 thermal
solutions available from VersaLogic – the HDW-406 heat sink with or without the HDW-411
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-3311 needs to be maintained at 85 ºC or below. This may
prove to be challenging depending on how and where the EPU-3311 is mounted in the end user
system.
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