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TDA7496SA Datasheet, PDF (10/13 Pages) STMicroelectronics – 5W+5W AMPLIFIER WITH DC VOLUME CONTROL | |||
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TDA7496SA
HEAT SINK DIMENSIONING:
In order to avoid the thermal protection intervention, that is placed approximatively at Tj = 150°C, it is important
the dimensioning of the Heat Sinker RTh (°C/W).
The parameters that influence the dimensioning are:
â Maximum dissipated power for the device (Pdmax)
â Max thermal resistance Junction to case (RTh j-c)
â Max. ambient temperature Tamb max
â Quiescent current Iq (mA)
Example:
VCC = 22V, Rload = 8ohm, RTh j-c = 5 °C/W , Tamb max = 50°C
Pdmax
=
(N°
channels)
·
----------V----c---c--2-----------
2Î 2 â
Rload
+
Iq
â
Vcc
Pdmax = 2 · ( 3.0 ) + 0.5 = 6.5 W
(Heat Sinker)
RTh c-a
=
1----5---0-----â-----T---a---m-----b----m----a---x-
Pd max
â
RTh
j-c
=
-1---5---0-----â----5----0-- â 5.0
6.5
=
10°C /W
In figure 23 is shown the Power derating curve for the device.
Figure 23. Power derating curve
20
15
(a)
10
(b)
5
(c)
a) Infinite Heatsink
b) 7 °C/ W
c) 10 °C/ W
0
0
40
80
120
160
Tamb (°C)
10/13
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