STA333BW13TR Datasheet, PDF (64/68 Pages) STMicroelectronics – 2.1-channel 40-watt high-efficiency digital audio system

Package thermal characteristics
9
Package thermal characteristics
STA333BW
Using a double-layer PCB the thermal resistance, junction to ambient, with 2 copper ground
areas of 3 x 3 cm² and with 16 via holes is 24 °C/W in natural air convection.
The dissipated power within the device depends primarily on the supply voltage, load
impedance and output modulation level.
Thus, the maximum estimated dissipated power for the STA333BW is:
2 x 20 W @ 8 , 18 V
Pd max is approximately 4 W
2 x 9 W + 1 x 20 W @ 4 , 8 ,18 V Pd max is approximately 5 W
Figure 22 shows the power derating curve for the PowerSSO-36 package on PCBs with
copper areas of 2 x 2 cm² and 3 x 3 cm².
Figure 22. PowerSSO-36 power derating curve
Pd (W) 8
7
6
5
4
3
2
1
0
0
Copper Area 3x3 cm
and via holes
Copper Area 2x2 cm
and via holes
ST_SA_TA3₃3₃3_9BB_WW
Po^Pw^SSe^OrS³⁶SO-
20 40 60 80 100 120 140 160
Tamb ( °C)
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