Emerson MVME55006E manual Thermal Validation, Thermally Significant Components

Thermal Validation

B

B.1 Overview

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 Appendix A, Specifications, 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.

B.2 Thermally Significant Components

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 Figure B-2and Figure B-1. 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.

Table B-1 Thermally Significant Components

			Max. Allowable
			Component
	Reference		Temperature	Measurement
	Designator	Generic Description	(deg. C)	Location
	U2, U3	Flash, soldered	85	Ambient
	U16	Gigabit Ethernet	119	Case
	U22	System controller	110	Case
	U24	MPC7457 processor	103	Case
MVME55006E Single-Board Computer Installation and Use (6806800A37D)				99