OPA1632 Datasheet, PDF (9/12 Pages) Texas Instruments – High-Perfomance, Fully-Differential AUDIO OP AMP

OPA1632
www.ti.com
POWER DISSIPATION AND THERMAL
CONSIDERATIONS
The OPA1632 does not have thermal shutdown
protection. Take care to assure that the maximum
junction temperature is not exceeded. Excessive
junction temperature can degrade performance or
cause permanent damage. For best performance and
reliability, assure that the junction temperature does not
exceed 125°C.
The thermal characteristics of the device are dictated
by the package and the circuit board. Maximum power
dissipation for a given package can be calculated using
the following formula:
P _Dmax
+
T_max *
q_JA
T_A
(1)
Where:
P_Dmax is the maximum power dissipation in the
amplifier (W).
T_max is the absolute maximum junction
temperature (_C).
T_A is the ambient temperature (_C).
q_JA = q_JC + q_CA.
q_JC is the thermal coefficient from the silicon
junctions to the case (_C/W).
q_CA is the thermal coefficient from the case to
ambient air (_C/W).
SBOS286 − DECEMBER 2003
For systems where heat dissipation is more critical, the
OPA1632 is offered in an MSOP-8 with PowerPAD.
The thermal coefficient for the MSOP PowerPAD
(DGN) package is substantially improved over the
traditional SO package. Maximum power dissipation
levels are depicted in Figure 5 for the two packages.
The data for the DGN package assumes a board layout
that follows the PowerPAD layout guidelines.
MAXIMUM POWER DISSIPATION
vs AMBIENT TEMPERATURE
3.5
θ
JA
=
170_ C/W
for
SO−8
(D)
3.0
θ
JA
=
58.4_ C/W
for
M S O P−8
(DGN)
T_J = 150_ C
No Airflow
2.5
MSOP−8 (DGN) Package
2.0
1.5
1.0
SO−8 (D) Package
0.5
0
−40
−15
10
35
60
85
Ambient Temperature (_ C)
Figure 5. Maximum Power Dissipation vs Ambient
Temperature
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