TRK-USB-MPC5643L Freescale Semiconductor, TRK-USB-MPC5643L Datasheet - Page 80

• Manufacturer Part Number: TRK-USB-MPC5643L
• Description: Development Boards & Kits - Other Processors StarTrakMiniUSG MPC5643L
• Manufacturer: Freescale Semiconductor

Specifications of TRK-USB-MPC5643L

• Rohs: yes
• Product: Starter Kits
• Tool Is For Evaluation Of: MPC5643L
• Core: Five Stage Pipeline
• Interface Type: LIN, DSPI
• Operating Supply Voltage: 3 V to 3.6 V
• Data Bus Width: 32 bit, 64 bit
• Description/function: Starter Kit for MPC5643L
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• For Use With: MPC5643L

Electrical characteristics
3.4.1
An estimation of the chip junction temperature, T
The junction to ambient thermal resistance is an industry standard value that provides a quick and easy estimation of thermal
performance. Unfortunately, there are two values in common usage: the value determined on a single layer board and the value
obtained on a board with two planes. For packages such as the PBGA, these values can be different by a factor of two. Which
value is closer to the application depends on the power dissipated by other components on the board. The value obtained on a
single layer board is appropriate for the 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.
When a heat sink is used, the thermal resistance is expressed in
and a case to ambient thermal resistance:
R
ambient thermal resistance, R
interface material, the mounting arrangement on printed circuit board, or change the thermal dissipation on the printed circuit
board surrounding the device.
To determine the junction temperature of the device in the application when heat sinks are not used, the Thermal
Characterization Parameter (
the top center of the package case using
The thermal characterization parameter is measured per JESD51-2 specification using a 40 gauge type T thermocouple epoxied
to the top center of the package case. The thermocouple should be positioned so that the thermocouple junction rests on the
package. A small amount of epoxy is placed over the 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.
3.4.1.1
Semiconductor Equipment and Materials International
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JC
is device related and cannot be influenced by the user. The user controls the thermal environment to change the case to
where:
T
R
P
where:
R
R
R
where:
T

P
A
D
D
T
JA
JA
JC
CA
JT
General notes for specifications at maximum junction temperature
References
= ambient temperature for the package (
= junction to ambient thermal resistance (
= power dissipation in the package (W)
= junction to ambient thermal resistance (°C/W)
= junction to case thermal resistance (°C/W)
= case to ambient thermal resistance (°C/W)
= thermocouple temperature on top of the package (°C)
= thermal characterization parameter (°C/W)
= power dissipation in the package (W)
CA
JT
) can be used to determine the junction temperature with a measurement of the temperature at
. For instance, the user can change the size of the heat sink, the air flow around the device, the
MPC5643L Microcontroller Data Sheet, Rev. 8.1
Equation
R
T
T
JA
J
J
J
3:
, can be obtained from
= T
= T
= R
A
T
+ (R
+ (
JC
o
C)
o
C/W)
JA
JT
+ R
Equation 2
× P
× P
CA
D
D
)
)
Equation
as the sum of a junction to case thermal resistance
1:
Freescale Semiconductor
Eqn. 1
Eqn. 2
Eqn. 3