Datasheet

ADSP-BF534/ADSP-BF536/ADSP-BF537
Rev. I|Page 57 of 68 | July 2010
THERMAL CHARACTERISTICS
To determine the junction temperature on the application
printed circuit board use:
where:
T
J
= Junction temperature (°C)
T
CASE
= Case temperature (°C) measured by customer at top
center of package.
Ψ
JT
= From Table 46
P
D
= Power dissipation (see the power dissipation discussion
and the tables on Page 28 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:
where:
T
A
= Ambient temperature (°C)
Values of θ
JC
are provided for package comparison and printed
circuit board design considerations when an external heat sink
is required. Values of θ
JB
are provided for package comparison
and printed circuit board design considerations.
In Table 46 through Table 48, airflow measurements comply
with JEDEC standards JESD51-2 and JESD51-6, and the junc-
tion-to-board measurement complies with JESD51-8. Test
board and thermal via design comply with JEDEC standards
JESD51-9 (BGA). The junction-to-case measurement complies
with MIL-STD-883 (Method 1012.1). All measurements use a
2S2P JEDEC test board.
Industrial applications using the 208-ball BGA package require
thermal vias, to an embedded ground plane, in the PCB. Refer to
JEDEC standard JESD51-9 for printed circuit board thermal
ball land and thermal via design information.
T
J
T
CASE
Ψ
JT
P
D
×()+=
T
J
T
A
θ
JA
P
D
×()+=
Table 46. Thermal Characteristics (182-Ball BGA)
Parameter ConditionTypica l Unit
θ
JA
0 Linear m/s Airflow 32.80 °C/W
θ
JMA
1 Linear m/s Airflow 29.30 °C/W
θ
JMA
2 Linear m/s Airflow 28.00 °C/W
θ
JB
20.10 °C/W
θ
JC
7.92 °C/W
Ψ
JT
0 Linear m/s Airflow 0.19 °C/W
Ψ
JT
1 Linear m/s Airflow 0.35 °C/W
Ψ
JT
2 Linear m/s Airflow 0.45 °C/W
Table 47. Thermal Characteristics (208-Ball BGA without
Thermal Vias in PCB)
Parameter ConditionTypica l Unit
θ
JA
0 Linear m/s Airflow 23.30 °C/W
θ
JMA
1 Linear m/s Airflow 20.20 °C/W
θ
JMA
2 Linear m/s Airflow 19.20 °C/W
θ
JB
13.05 °C/W
θ
JC
6.92 °C/W
Ψ
JT
0 Linear m/s Airflow 0.18 °C/W
Ψ
JT
1 Linear m/s Airflow 0.27 °C/W
Ψ
JT
2 Linear m/s Airflow 0.32 °C/W
Table 48. Thermal Characteristics (208-Ball BGA with
Thermal Vias in PCB)
Parameter ConditionTypica l Unit
θ
JA
0 Linear m/s Airflow 22.60 °C/W
θ
JMA
1 Linear m/s Airflow 19.40 °C/W
θ
JMA
2 Linear m/s Airflow 18.40 °C/W
θ
JB
13.20 °C/W
θ
JC
6.85 °C/W
Ψ
JT
0 Linear m/s Airflow 0.16 °C/W
Ψ
JT
1 Linear m/s Airflow 0.27 °C/W
Ψ
JT
2 Linear m/s Airflow 0.32 °C/W