TDA7491HV Datasheet, PDF (24/26 Pages) STMicroelectronics – 20 W + 20 W dual BTL class-D audio amplifier

Application information
TDA7491HV
7.9
Heatsink requirements
A thermal resistance of 24° C/W can be obtained using the PCB copper ground layer with
16 vias connecting it to the contact area for the slug. Ensure that the copper ground area is
a nominal 9 cm² for 24° C/W.
Figure 31 shows the derating curves for copper areas of 4 cm² and 9 cm².
As with most amplifiers, the power dissipated within the device depends primarily on the
supply voltage, the load impedance and the output modulation level.
The maximum estimated power dissipation for the TDA7491HV is less than 4 W. When
properly mounted on the above PCB the junction temperature could increase by 96° C.
However, with a musical program the dissipated power is about 40% less, leading to a
temperature increase of around 60° C. Even at the maximum recommended ambient
temperature for consumer applications of 50° C there is still a clear safety margin before the
maximum junction temperature (150° C) is reached.
Figure 31. Power derating curves for PCB used_gas heatsink
Pd (W) ⁸
7
6
Copper Area 3x3 cm
and via holes
5
T^TD^DA^A7⁷49⁴1⁹P^1HV
PPSSSSOO36-36
4
3
2
Copper Area 2x2 cm
and via holes
1
0
0 20 40 60 80 100 120 140
Tamb ( °C)
160
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