Application information

TDA7491MV

26/28

Doc ID 14576 Rev 2

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 exposed pad. Ensure that the copper ground

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 TDA7491MV 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 27.

Power derating curves for PCB used as heatsink

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1

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3

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5

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7

8

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20

40

60

80

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120

140

160

g

Pd (W)

Tamb ( °C)

Copper Area 2x2 cm

and via holes

TDA7491P

PSSO36

Copper Area 3x3 cm

and via holes

TDA7491MV

PowerSSO-36