English
Language : 

STCS1_08 Datasheet, PDF (11/17 Pages) STMicroelectronics – 1.5 A max constant current LED driver
STCS1
Application information
– Package: DFN8 3x3 mm;
– TA = 50 °C;
In this case VDRAIN = 12 - 3 x 3.6 = 1.2 V
PD = (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:
TJ = 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 12. Maximum power dissipation vs TA Figure 13. Maximum power dissipation vs TA
for DFN8 3x3 mm
for PowerSO-8
3.50
3.00
RthJA = 38 [°C/W]
2.50
2.00
1.50
1.00
0.50
PDMAX = (TJMAX-TA)/RthJA
0.00
25 35 45 55 65 75 85
[°C]
95 105 115 125
3.00
RthJA = 45 [°C/W]
2.50
2.00
1.50
1.00
0.50
PDMAX = (TJMAX-TA)/RthJA
0.00
25 35 45 55 65 75 85
[°C]
95 105 115 125
11/17