STA333BW_11 STMICROELECTRONICS [STMicroelectronics], STA333BW_11 Datasheet - Page 63

• Manufacturer Part Number: STA333BW_11
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

STA333BW
8
Package thermal characteristics
Using a double-layer PCB the thermal resistance, junction to ambient, with 2 copper ground
areas of 3 x 3 cm
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:
Figure 21
copper areas of 2 x 2 cm
Figure 21. PowerSSO-36 power derating curve
2 x 20 W @ 8 Ω, 18 V
2 x 9 W + 1 x 20 W @ 4 Ω, 8 Ω, 18 V
shows the power derating curve for the PowerSSO-36 package on PCBs with
Pd (W)
Pd (W)
2
and with 16 via holes is 24 °C/W in natural air convection.
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0
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and 3 x 3 cm
Copper Area 2x2 cm
Copper Area 2x2 cm
and via holes
and via holes
20
20
20
20
20
Doc ID 13773 Rev 3
40
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40
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40
Copper Area 3x3 cm
Copper Area 3x3 cm
and via holes
and via holes
2
.
60
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60
60
Tamb ( °C)
Tamb ( °C)
Pd max is approximately 4 W
Pd max is approximately 5 W
80
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100
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100
Package thermal characteristics
STA333BW
PowerSSO-36
120
120
120
120
120
STA339BW
STA339BW
PSSO36
PSSO36
140
140
140
140
140
160
160
160
160
160
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