© National Instruments
|
4-7
NI sbRIO-9651 System on Module Carrier Board Design Guide
NI sbRIO devices integrated into an enclosure or system with proper thermal dissipation can
be deployed in high- and low-temperature environments. However, the 85 °C local ambient
operating temperature rating of the sbRIO-9651 SOM does not mean that the external
temperature of the natural convection environment such as a room or larger enclosure can be
85 °C. In this way, properly designed NI sbRIO devices may still require an external ambient
temperature of 70 °C or less and may still require specific mounting requirements to ensure that
the local ambient and thermally-relevant component maximum operating temperatures are
within specification.
Understanding Thermal Specifications
A deployed system has several temperature measurement locations that indicate the thermal
performance of the system and the devices the system contains. For example, in a natural
convection system, the temperature of a critical component will be higher than the temperature
of the air in the immediate vicinity of the component. This local air temperature will also be
higher inside an enclosure than in the room ambient that surrounds the enclosure.
Figure 4-4 identifies these types of ambient temperatures.
Figure 4-4.
Ambient Temperatures
1
External ambient temperature
2
Internal/enclosure ambient temperature
3
Carrier board
4
sbRIO-9651 SOM
5
Local ambient temperature
6
Enclosure
4
5
2
1
6
3