Preliminary Technical Data
ENVIRONMENTAL CONDITIONS
To determine the junction temperature on the application
printed circuit board use:
TJ = TCASE + (ΨJT × PD)
where:
TJ = Junction temperature (؇C)
TCASE = Case temperature (؇C) measured by customer at top
center of package.
ΨJT = From Table 58
PD = Power dissipation — For a description, see Total Power
Dissipation on Page 33.
Values of θJA are provided for package comparison and printed
circuit board design considerations. θJA can be used for a first
order approximation of TJ by the equation:
TJ = TA + (θJA × PD)
where:
TA = Ambient temperature (؇C)
Values of θJC are provided for package comparison and printed
circuit board design considerations when an external heat sink
is required.
Values of θJB are provided for package comparison and printed
circuit board design considerations.
In Table 58, airflow measurements comply with JEDEC stan-
dards JESD51-2 and JESD51-6, and the junction-to-board
measurement complies with JESD51-8. The junction-to-case
measurement complies with MIL-STD-883 (Method 1012.1).
All measurements use a 2S2P JEDEC test board.
Table 57. Thermal Characteristics (BC-208-1)
Parameter
θJA
θJMA
θJMA
θJB
θJC
ΨJT
ΨJT
ΨJT
Condition
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
Typical
23.20
20.20
19.20
13.05
6.92
0.18
0.27
0.32
Unit
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
ADSP-BF522/523/524/525/526/527
Table 58. Thermal Characteristics (BC-289-2)
Parameter
θJA
θJMA
θJMA
θJB
θJC
ΨJT
ΨJT
ΨJT
Condition
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
0 linear m/s air flow
1 linear m/s air flow
2 linear m/s air flow
Typical
34.5
31.1
29.8
20.3
8.8
0.24
0.44
0.53
Unit
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
Rev. PrG | Page 71 of 80 | February 2009