mpc8641 Freescale Semiconductor, Inc, mpc8641 Datasheet - Page 109

• Manufacturer Part Number: mpc8641
• Description: Integrated Host Processor Hardware Specifications
• Manufacturer: Freescale Semiconductor, Inc

19 Thermal
This section describes the thermal specifications of the MPC8641.
19.1
Table 71
19.2 Thermal Management Information
This section provides thermal management information for the high coefficient of thermal expansion
(HCTE) package for air-cooled applications. Proper thermal control design is primarily dependent on the
system-level design—the heat sink, airflow, and thermal interface material. The MPC8641 implements
several features designed to assist with thermal management, including the temperature diode. The
temperature diode allows an external device to monitor the die temperature in order to detect excessive
temperature conditions and alert the system; see
information.
To reduce the die-junction temperature, heat sinks are required; due to the potential large mass of the heat
sink, attachment through the printed-circuit board is suggested. In any implementation of a heat sink
solution, the force on the die should not exceed ten pounds force (45 newtons).
clip through the board. Occasionally the spring clip is attached to soldered hooks or to a plastic backing
structure. Screw and spring arrangements are also frequently used.
Freescale Semiconductor
Junction-to-ambient thermal resistance, natural convection, single-layer (1s) board
Junction-to-ambient thermal resistance, natural convection, four-layer (2s2p) board
Junction-to-ambient thermal resistance, 200 ft/min airflow, single-layer (1s) board
Junction-to-ambient thermal resistance, 200 ft/min airflow, four-layer (2s2p) board
Junction-to-board thermal resistance
Junction-to-case thermal resistance
Notes:
1. Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting site (board)
2. Per JEDEC JESD51-2 with the single-layer board (JESD51-3) horizontal.
3. Per JEDEC JESD51-6 with the board (JESD51-7) horizontal.
4. Thermal resistance between the die and the printed-circuit board per JEDEC JESD51-8. Board temperature is measured on
5. This is the thermal resistance between die and case top surface as measured by the cold plate method (MIL SPEC-883
temperature, ambient temperature, air flow, power dissipation of other components on the board, and board thermal
resistance.
the top surface of the board near the package.
Method 1012.1) with the calculated case temperature. Actual thermal resistance is less than 0.1 °C/W.
provides the package thermal characteristics for the MPC8641.
Thermal Characteristics
MPC8641 and MPC8641D Integrated Host Processor Hardware Specifications, Rev. 2
Characteristic
Table 71. Package Thermal Characteristics
Section 19.2.4, “Temperature Diode,”
1
Symbol
R
R
R
R
R
R
θ
θ
θ
θ
θ
θ
JMA
JMA
JC
JA
JA
JB
Figure 59
Value
< 0.1
18
13
13
9
5
for more
shows a spring
°
°
°
°
°
°
Unit
C/W
C/W
C/W
C/W
C/W
C/W
Thermal
Notes
1, 2
1, 3
1, 3
1, 3
4
5
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