Motorola 700/800-Series User Manual
Introduction
1-11
1
The MVME162LX uses commercial-grade devices. Therefore, it can
operate in an environment with ambient air temperatures from 0û C
to 70û C. Several factors influence the ambient temperature seen by
components on the MVME162LX. Among them are inlet air
temperature; airflow characteristics; number, types, and locations
of IP modules; power dissipation of adjacent boards in the system,
etc.
operate in an environment with ambient air temperatures from 0û C
to 70û C. Several factors influence the ambient temperature seen by
components on the MVME162LX. Among them are inlet air
temperature; airflow characteristics; number, types, and locations
of IP modules; power dissipation of adjacent boards in the system,
etc.
A temperature profile of a comparable board (the MVME172
embedded controller) was developed in an MVME954A six-slot
VME chassis. Two such boards, each loaded with one 4MB memory
mezzanine and two GreenSpring IndustryPack modules, were
placed in the chassis with one 36W load board installed between
them. The chassis was placed in a thermal chamber that maintained
an ambient temperature of 55û C. Measurements showed that the
fans in the chassis supplied an airflow of approximately 65 LFM
over the MVME172 boards. Under these conditions, a rise in
temperature of approximately 10û C between the inlet and exit air
was observed. The junction temperatures of selected high-power
devices on the MVME172 were calculated (from case temperature
measurements) and were found to be within manufacturersÕ
specified tolerances.
embedded controller) was developed in an MVME954A six-slot
VME chassis. Two such boards, each loaded with one 4MB memory
mezzanine and two GreenSpring IndustryPack modules, were
placed in the chassis with one 36W load board installed between
them. The chassis was placed in a thermal chamber that maintained
an ambient temperature of 55û C. Measurements showed that the
fans in the chassis supplied an airflow of approximately 65 LFM
over the MVME172 boards. Under these conditions, a rise in
temperature of approximately 10û C between the inlet and exit air
was observed. The junction temperatures of selected high-power
devices on the MVME172 were calculated (from case temperature
measurements) and were found to be within manufacturersÕ
specified tolerances.
!
Caution
For elevated-temperature operation, perform similar
measurements and calculations to determine the actual
operating margin for your specific environment.
measurements and calculations to determine the actual
operating margin for your specific environment.
To facilitate elevated-temperature operation:
1. Position the MVME162LX in the chassis to permit maximum
airflow over the component side of the board.
2. Do not place boards with high power dissipation next to the
MVME162LX.
3. Use low-power IP modules only.