Emerson MVME55006E Manuel D’Utilisation

Board component temperatures are affected by ambient temperature, air flow, board electrical 
operation and software operation. In order to evaluate the thermal performance of a circuit 
board assembly, it is necessary to test the board under actual operating conditions. These 
operating conditions vary depending on system design.

While Emerson performs thermal analysis in a representative system to verify operation within 
specified ranges, refer to 

, you should evaluate the thermal 

performance of the board in your application.

This appendix provides systems integrators with information which can be used to conduct 
thermal evaluations of the board in their specific system configuration. It identifies thermally 
significant components and lists the corresponding maximum allowable component operating 
temperatures. It also provides example procedures for component-level temperature 
measurements.

The following table summarizes components that exhibit significant temperature rises. These 
are the components that should be monitored in order to assess thermal performance. The 
table also supplies the component reference designator and the maximum allowable operating 
temperature.

You can find components on the board by their reference designators as shown in 

 

and 

. Versions of the board that are not fully populated may not contain some of these 

components.

The preferred measurement location for a component may be junction, case, or air as specified 
in the table. Junction temperature refers to the temperature measured by an on-chip thermal 
device. Case temperature refers to the temperature at the top, center surface of the component. 
Air temperature refers to the ambient temperature near the component.

U2, U3

Flash, soldered

85

Ambient

U16

Gigabit Ethernet

119

Case

U22

System controller

110

Case

U24

MPC7457 processor

103

Case