STCS1A Datasheet, PDF (13/19 Pages) STMicroelectronics – 1.5 A max constant current LED driver

STCS1A
Application information
– LEDs current: 500 mA;
– Package: DFN8 3x3 mm;
– T_A = 50°C;
In this case V_DRAIN = 12 - 3 x 3.6 = 1.2 V
P_D = (1.2 - 0.1) x 0.5 + 12 x 0.5 x 10^-3 = 0.55 + 6 x 10^-3 = 556 mW
The junction temperature will be:
T_J = 37.6 x 0.556 + 50 = 70.9 °C
The following pictures show the maximum power dissipation according to the ambient
temperature for both packages:
Figure 16. Maximum power dissipation vs T_A Figure 17. Maximum power dissipation vs T_A
for DFN8 3x3 mm
for PowerSO-8
3.50
3.00
R_thJA = 38 [°C/W]
2.50
2.00
1.50
1.00
0.50
0.00 ^{PDMAX = (TJMAX-TA)/RthJA}
25 35 45 55 65 75 85
[°C]
95 105 115 125
3.00
R_thJA = 45 [°C/W]
2.50
2.00
1.50
1.00
0.50
P_DMAX = (T_JMAX-T_A)/R_thJA
0.00
25 35 45 55 65 75 85
[°C]
95 105 115 125
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