MPC8309VMAHFCA Freescale Semiconductor, MPC8309VMAHFCA Datasheet - Page 73

• Manufacturer Part Number: MPC8309VMAHFCA
• Description: 417/333/233 MP Std Tmp
• Manufacturer: Freescale Semiconductor

Specifications of MPC8309VMAHFCA

• Processor Series: MPC8309
• Core: e300c3
• Data Bus Width: 32 bit
• Data Ram Size: 512 MB
• Interface Type: USB, CAN, UART, PCI
• Maximum Clock Frequency: 417 MHz
• Number Of Programmable I/os: 56
• Operating Supply Voltage: - 0.3 V to + 1.26 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: 0 C to + 105 C
• Processor To Be Evaluated: MPC8309
• Supply Current (max): 5 uA
• Lead Free Status / Rohs Status: Details

The junction-to-ambient thermal resistance is an industry standard value that provides a quick and easy
estimation of thermal performance. As a general statement, the value obtained on a single layer board is
appropriate for a tightly packed printed-circuit board. The value obtained on the board with the internal
planes is usually appropriate if the board has low power dissipation and the components are well separated.
Test cases have demonstrated that errors of a factor of two (in the quantity T
24.1.3
The thermal performance of a device cannot be adequately predicted from the junction-to-ambient thermal
resistance. The thermal performance of any component is strongly dependent on the power dissipation of
surrounding components. In addition, the ambient temperature varies widely within the application. For
many natural convection and especially closed box applications, the board temperature at the perimeter
(edge) of the package is approximately the same as the local air temperature near the device. Specifying
the local ambient conditions explicitly as the board temperature provides a more precise description of the
local ambient conditions that determine the temperature of the device.
At a known board temperature, the junction temperature is estimated using the following equation:
where:
When the heat loss from the package case to the air can be ignored, acceptable predictions of junction
temperature can be made. The application board should be similar to the thermal test condition: the
component is soldered to a board with internal planes.
24.1.4
To determine the junction temperature of the device in the application after prototypes are available, the
thermal characterization parameter (
measurement of the temperature at the top center of the package case using the following equation:
where:
Freescale Semiconductor
MPC8309 PowerQUICC II Pro Integrated Communications Processor Family Hardware Specifications, Rev. 1
T
R
P
T
T
R
P
T
A
J
B
J

D

D
JA
JB
= junction temperature (C)
= junction temperature (C)
= ambient temperature for the package (C)
= board temperature at the package perimeter (C)
= power dissipation in the package (W)
= power dissipation in package (W)
Estimation of Junction Temperature with Junction-to-Board
Thermal Resistance
Experimental Determination of Junction Temperature
= junction-to-ambient thermal resistance (C/W)
= junction-to-board thermal resistance (C/W) per JESD51-8
JT
T
T
J
) can be used to determine the junction temperature with a
J
= T
= T
B
T
+ (R  J
+ (

JT
B


P
P
D
D
)
)
J
– T
A
) are possible.
Thermal
Eqn. 2
Eqn. 3
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