mpc8343e Freescale Semiconductor, Inc, mpc8343e Datasheet - Page 70

• Manufacturer Part Number: mpc8343e
• Description: Mpc8343e Powerquicc
• Manufacturer: Freescale Semiconductor, Inc

Thermal
thermocouple junction and over about 1 mm of wire extending from the junction. The thermocouple wire
is placed flat against the package case to avoid measurement errors caused by cooling effects of the
thermocouple wire.
20.2.4
Some application environments require a heat sink to provide the necessary thermal management of the
device. When a heat sink is used, the thermal resistance is expressed as the sum of a junction-to-case
thermal resistance and a case-to-ambient thermal resistance:
where:
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.
The thermal performance of devices with heat sinks 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 56
70
θ
f
JC
AAVID 30 × 30 × 9.4 mm pin fin
AAVID 30 × 30 × 9.4 mm pin fin
AAVID 30 × 30 × 9.4 mm pin fin
AAVID 31 × 35 × 23 mm pin fin
AAVID 31 × 35 × 23 mm pin fin
AAVID 31 × 35 × 23 mm pin fin
Wakefield, 53 × 53 × 25 mm pin fin
Wakefield, 53 × 53 × 25 mm pin fin
Wakefield, 53 × 53 × 25 mm pin fin
MEI, 75 × 85 × 12 no adjacent board, extrusion
MEI, 75 × 85 × 12 no adjacent board, extrusion
is device-related and cannot be influenced by the user. The user controls the thermal environment to
R
R
R
θ
θ
θ
shows heat sink thermal resistance for PBGA of the MPC8343E.
JA
JC
CA
MPC8343E PowerQUICC™ II Pro Integrated Host Processor Hardware Specifications, Rev. 11
Heat Sinks and Junction-to-Case Thermal Resistance
= junction-to-ambient thermal resistance (°C/W)
= junction-to-case thermal resistance (°C/W)
= case-to-ambient thermal resistance (°C/W)
Heat Sink Assuming Thermal Grease
Table 56. Heat Sink and Thermal Resistance of MPC8343E (PBGA)
R
θ
JA
= R
θ
JC
+ R
θ
CA
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
Thermal Resistance
29 × 29 mm PBGA
Freescale Semiconductor
13.5
11.3
10.1
9.6
8.8
8.1
7.5
9.1
7.1
6.5
7.7