STCS2 STMicroelectronics, STCS2 Datasheet - Page 11

• Manufacturer Part Number: STCS2
• Description: 1.5A MAX CONSTANT CURRENT LED DRIVER
• Manufacturer: STMicroelectronics

Figure 12. Maximum power dissipation vs T
basing on this and on the thermal resistance and ambient temperature, the junction
temperature can be calculated as:
T
A typical application could be:
In this case the drain voltage is given by:
V
end the power dissipated in the IC is the following:
P
With a thermal resistance junction-ambient equal to 12 °C/W the junction temperature is:
T
The following pictures show the maximum power dissipation according to the ambient
temperature:
J
J
DRAIN
D
= R
= 12 x 1.1 + 50 = 63 °C.
– Input Voltage: 12 V;
– 3 white LEDs with an typical V
– LEDs current: 1000 mA;
– Package: Power SO-10;
– T
= (1.2 - 0.1) x 1 + 12 x 0.5 x 10
12.00
12.00
10.00
10.00
8.00
8.00
6.00
6.00
4.00
4.00
2.00
2.00
0.00
0.00
thJA
A
= 12 - 3 x 3.6 = 1.2 V
= 50 °C;
x P
25
25
D
+ T
35
35
A
P
P
DMAX
DMAX
45
45
= (T
= (T
55
55
JMAX
JMAX
-3
A
= 1.1 W
F
for PowerSO-10
65
65
= 3.6 V;
-T
-T
A
A
)/R
)/R
[°C]
[°C]
75
75
thJA
thJA
85
85
95 105 115 125
95 105 115 125
R
R
thJA
thJA
[°C/W]
[°C/W]
12
12
35
35
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