ADSP-BF538 Datasheet, PDF (50/56 Pages) Analog Devices – Blackfin Embedded Processor

ADSP-BF538/ADSP-BF538F
THERMAL CHARACTERISTICS
To determine the junction temperature on the application
printed circuit board use:
T_J = T_CASE + (Ψ_JT × P_D)
where:
T_J = Junction temperature (؇C)
T_CASE = Case temperature (؇C) measured by customer at top
center of package.
Ψ_JT = From Table 36
P_D = Power dissipation (see Power Dissipation on Page 46 for
the method to calculate P_D)
Values of θ_JA are provided for package comparison and printed
circuit board design considerations. θ_JA can be used for a first
order approximation of T_J by the equation:
T_J = T_A + (θ_JA × P_D)
where:
T_A = Ambient temperature (؇C)
Values of θ_JC are provided for package comparison and printed
circuit board design considerations when an external heatsink is
required.
Values of θ_JB are provided for package comparison and printed
circuit board design considerations.
In Table 36, 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 36. Thermal Characteristics 316-ball BGA
Parameter
θ_JA
θ_JMA
θ_JMA
θ_JB
θ_JC
ψ_JT
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
Typical
TBD
TBD
TBD
TBD
TBD
TBD
Unit
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
؇C/W
Preliminary Technical Data
Rev. PrD | Page 50 of 56 | May 2006