TDA7495SA_07 Datasheet, PDF (11/15 Pages) STMicroelectronics – 11 W + 11 W amplifier with DC volume control

TDA7495SA
4
Thermal considerations
Thermal considerations
In order to avoid the intervention of the thermal protection, it is important to choose an
adequate heatsink.
The parameters that influence the heatsink size are:
" maximum dissipated power for the device (P_dmax)
" maximum thermal resistance junction to case (R_{Th j-c})
" maximum ambient temperature T_{amb_max}
Example:
For V_CC = 20 V, R_L = 8 Ω, R_{Th j-c} = 5° C/W, T_{amb_max} = 50° C
P_dmax = Number_of_channels *
-----^V-----^c---^c---²-------
2Π² ⋅ R_L
=5W
For the heatsink,
R_{Th j-c}
=
1_----5_---0_{-----–-----}T_{---a---m----b---_---m---a---x-}
P_{d max}
–
R_Th
j-c
=
1_----0_---0_{-- – 5}
5
=
15°C/W
Figure 25 shows the power derating curve for the device.
Figure 25. Power derating curve
20
15
(d)
(a)
10
(b)
5
(c)
a) Infinite Heatsink
b) 7 °C/ W
c) 10 °C/ W
d) 3.3 °C/ W
0
0
40
80
120
160
Tamb (°C)
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