6
Table 10-3 LQFP Package Thermal Characteristics
Value
(LQFP)
Characteristic
Symbol
Unit
Notes
Comments
Junction to ambient
Natural convection
Single layer board
(1s)
RθJA
74
50
°C/W
°C/W
1,2
1,3
Junction to ambient
Natural convection
Four layer board
(2s2p)
RθJMA
Junction to ambient
(@200 ft/min)
Single layer board
(1s)
RθJMA
67
46
°C/W
°C/W
1,3
1,3
Junction to ambient
(@200 ft/min)
Four layer board
(2s2p)
RθJMA
Junction to board
RθJB
RθJC
ΨJT
23
20
4
°C/W
°C/W
°C/W
4
5
6
Junction to case
Junction to package top
Natural Convection
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 SEMI G38-87 and JEDEC JESD51-2 with the single layer board horizontal.
3. Per JEDEC JESC51-6 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. When Greek letters are not available, the thermal characterization parameter is written as Psi-JT.
7. See Section 12.1 for more details on thermal design considerations.
56F8014 Technical Data, Rev. 9
92
Freescale Semiconductor
Preliminary
FREESCALE [ Freescale ]
