THERMAL CHARACTERISTICS
To determine the junction temperature on the application
printed circuit board, use:
T
J
=
T
CASE
+
JT
P
D
where:
T
J
= Junction temperature (
°
C).
T
CASE
= Case temperature (
°
C) measured by customer at top
center of package.
JT
= From
through
P
D
= Power dissipation (see the power dissipation discussion
and the tables on
for the method to calculate P
D
).
Values of
JA
are provided for package comparison and printed
circuit board design considerations.
JA
can be used for a first
order approximation of
T
J
by the equation:
T
J
=
T
A
+
JA
P
D
where:
T
A
= ambient temperature (
°
C).
In
through
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
JA
in
through
is the figure
of merit relating to performance of the package and board in a
convective environment.
JMA
represents the thermal resistance
under two conditions of airflow.
JT
represents the correlation
between
T
J
and
T
CASE
.
Table 38. Thermal Characteristics for BC-160 Package
Parameter
JA
JMA
JMA
JC
JT
JT
JT
Condition
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
Not Applicable
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
Typical
27.1
23.85
22.7
7.26
0.14
0.26
0.35
Unit
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
Table 39. Thermal Characteristics for ST-176-1 Package
Parameter
JA
JMA
JMA
JT
JT
JT
Condition
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
Typical
34.9
33.0
32.0
0.50
0.75
1.00
Unit
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
Table 40. Thermal Characteristics for B-169 Package
Parameter
JA
JMA
JMA
JC
JT
JT
JT
Condition
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
Not Applicable
0 Linear m/s Airflow
1 Linear m/s Airflow
2 Linear m/s Airflow
Typical
22.8
20.3
19.3
10.39
0.59
0.88
1.37
Unit
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
°
C/W
Rev. I
|
Page 49 of 64 |
August 2013
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