Datasheet
Board type Symbol Description 324 MAPBGA Unit Notes
— Ψ
JB
Thermal
characterization
parameter, junction
to package top
natural convection)
2.65 °C/W 7
1. Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting site
(board) temperature, ambient temperature, air flow, power dissipation of other components on the board, and board
thermal resistance.,
2. Per JEDEC JESD51-2 with the single layer board horizontal. Board meets JESD51-9 specification.
3. Per JEDEC JESD51-6 with the board horizontal
4. Thermal resistance between the die and the printed circuit board per JEDEC JESD51-8. Board temperature is
measured on the top surface of the board near the package.
5. Thermal resistance between the die and the case top surface as measured by the cold plate method (MIL SPEC-883
Method 1012.1).
6. Thermal characterization parameter indicating the temperature difference between package top and the junction
temperature per JEDEC JESD51-2.
7. Thermal characterization parameter indicating the temperature difference between package bottom center and the
junction temperature per JEDEC JESD51-12. When Greek letters are not available, the thermal characterization
parameter is written as Psi-JB.
Board type Symbol Description 256 MAPBGA Unit Notes
Single-layer (1s) R
θJA
Thermal
resistance, junction
to ambient (natural
convection)
29.4 °C/W 1, 2
Four-layer (2s2p) R
θJA
Thermal
resistance, junction
to ambient (natural
convection)
19.3 °C/W 1,2, 3
Single-layer (1s) R
θJMA
Thermal
resistance, junction
to ambient (200 ft./
min. air speed)
21.4 °C/W 1,3
Four-layer (2s2p) R
θJMA
Thermal
resistance, junction
to ambient (200 ft./
min. air speed)
14.8 °C/W 1,3
— R
θJB
Thermal
resistance, junction
to board
11 °C/W 4
— R
θJC
Thermal
resistance, junction
to case
9.5 °C/W 5
— Ψ
JT
Thermal
characterization
parameter, junction
to package top
outside center
(natural
convection)
0.5 °C/W 6
Table continues on the next page...
Thermal attributes
MPC5748G Microcontroller Datasheet Data Sheet, Rev. 2, 05/2014.
62
Preliminary
Freescale Semiconductor, Inc.