Datasheet

ADSP-BF561
In Table 32 through Table 34, airflow measurements comply
with JEDEC standards JESD51–2 and JESD51–6, and the junc-
tion-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.
Thermal resistance θ
JA
in Table 32 through Table 34 is the figure
of merit relating to performance of the package and board in a
convective environment. θ
JMA
represents the thermal resistance
under two conditions of airflow. θ
JB
represents the heat
extracted from the periphery of the board. Ψ
JT
represents the
correlation between T
J
and T
CASE
. Values of θ
JB
are provided for
package comparison and printed circuit board design
considerations.
Table 32. Thermal Characteristics for BC-256-4
(17 mm × 17 mm) Package
Parameter Condition Typical Unit
θ
JA
0 Linear m/s Airflow 18.1 C/W
θ
JMA
1 Linear m/s Airflow 15.9 C/W
θ
JMA
2 Linear m/s Airflow 15.1 C/W
θ
JC
Not Applicable 3.72 C/W
Ψ
JT
0 Linear m/s Airflow 0.11 C/W
Ψ
JT
1 Linear m/s Airflow 0.18 C/W
Ψ
JT
2 Linear m/s Airflow 0.18 C/W
Table 33. Thermal Characteristics for BC-256-1
(12 mm × 12 mm) Package
Parameter Condition Typical Unit
θ
JA
0 Linear m/s Airflow 25.6 C/W
θ
JMA
1 Linear m/s Airflow 22.4 C/W
θ
JMA
2 Linear m/s Airflow 21.6 C/W
θ
JB
Not Applicable 18.9 C/W
θ
JC
Not Applicable 4.85 C/W
Ψ
JT
0 Linear m/s Airflow 0.15 C/W
Ψ
JT
1 Linear m/s Airflow n/a C/W
Ψ
JT
2 Linear m/s Airflow n/a C/W
Table 34. Thermal Characteristics for B-297 Package
Parameter Condition Typical Unit
θ
JA
0 Linear m/s Airflow 20.6 C/W
θ
JMA
1 Linear m/s Airflow 17.8 C/W
θ
JMA
2 Linear m/s Airflow 17.4 C/W
θ
JB
Not Applicable 16.3 C/W
θ
JC
Not Applicable 7.15 C/W
Ψ
JT
0 Linear m/s Airflow 0.37 C/W
Ψ
JT
1 Linear m/s Airflow n/a C/W
Ψ
JT
2 Linear m/s Airflow n/a C/W
Rev. E | Page 45 of 64 | September 2009