Motorola CPCI-6115 - Manual (Page 35)

Thermal Requirements Hardware Preparation and Installation
CPCI-6115 CompactPCI Single Board Computer Installation and Use (6806800A68D) 33
This section provides systems integrators with information that 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 sample procedures for component-level temperature
measurements.
Table 2-3 on page 33 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 2-1
on page 34 . 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 2-3 Thermally Significant Components
Component Location General Description
Maximum
Allowable
Temperature
(Degrees C) Measurement
Location
(Junction, Case or
Air)
U40 Ultra DMA PCI-IDE 70 ° C (158° F) Air
U36 21555BB PCI Bridge 70 ° C (158° F) Air
U32 MPC7457 Processor 103 ° C (217.4° F) Case
U23, U89 DDR Clock Generator 85 ° C (185° F) Air
U22 MV64360 110 ° C (230° F) Case
U159, U160 32 megabit flash 85 ° C (185° F) Air
U146 Clock Buffer 105 ° C (221° F) Case
U13, U14 Cache 115 ° C (239° F) Case
U2-U10, U74-U82 DDR SDRAM 70 ° C (158° F) Air
U101, U102, U96 Ethernet PHY 120 ° C (248° F) Case