MPC8358 FREESCALE [Freescale Semiconductor, Inc], MPC8358 Datasheet - Page 88

• Manufacturer Part Number: MPC8358
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Thermal
R
change the case to ambient thermal resistance, R
sink, the air flow around the device, the interface material, the mounting arrangement on printed circuit
board, or change the thermal dissipation on the printed circuit board surrounding the device.
To illustrate the thermal performance of the devices with heat sinks, the thermal performance has been
simulated with a few commercially available heat sinks. The heat sink choice is determined by the
application environment (temperature, air flow, adjacent component power dissipation) and the physical
space available. Because there is not a standard application environment, a standard heat sink is not
required.
Table 76
Accurate thermal design requires thermal modeling of the application environment using computational
fluid dynamics software which can model both the conduction cooling and the convection cooling of the
air moving through the application. Simplified thermal models of the packages can be assembled using the
junction-to-case and junction-to-board thermal resistances listed in the thermal resistance table. More
detailed thermal models can be made available on request.
88
θ
JC
is device related and cannot be influenced by the user. The user controls the thermal environment to
MPC8358E PowerQUICC™ II Pro Processor Revision 2.1 PBGA Silicon Hardware Specifications, Rev. 1
shows heat sinks and junction-to-case thermal resistance for PBGA package.
MEI, 75
MEI, 75
MEI, 75
Table 76. Heat Sinks and Junction-to-Case Thermal Resistance of PBGA Package
Heat Sink Assuming Thermal Grease
Wakefield, 53
Wakefield, 53
Wakefield, 53
AAVID 30
AAVID 30
AAVID 30
AAVID 31
AAVID 31
AAVID 31
×
×
×
85
85
85
×
×
×
12 no adjacent board, extrusion
12 no adjacent board, extrusion
12 no adjacent board, extrusion
R
R
R
×
×
×
×
×
×
θ
θ
θ
JA
JC
CA
30
30
30
×
×
×
35
35
35
53
53
53
= junction to ambient thermal resistance (°C/W)
×
×
×
= junction to case thermal resistance (°C/W)
×
×
×
= case to ambient thermal resistance (°C/W)
9.4 mm Pin Fin
9.4 mm Pin Fin
9.4 mm Pin Fin
×
×
×
23 mm Pin Fin
23 mm Pin Fin
23 mm Pin Fin
25 mm Pin Fin
25 mm Pin Fin
25 mm Pin Fin
θ
CA
. For instance, the user can change the size of the heat
Natural Convection
Natural Convection
Natural Convection
Natural Convection
Air Flow
1 m/s
2 m/s
1 m/s
2 m/s
1 m/s
2 m/s
1 m/s
2 m/s
Thermal Resistance
29
Freescale Semiconductor
×
29 mm PBGA
12.6
10.5
8.2
7.0
6.6
6.1
9.0
5.6
5.1
9.0
5.7
5.1