STCS2A STMicroelectronics, STCS2A Datasheet - Page 13

• Manufacturer Part Number: STCS2A
• Description: 1.5A MAX CONSTANT CURRENT LED DRIVER
• Manufacturer: STMicroelectronics

Figure 16. Maximum power dissipation vs T
P
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
D
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: PowerSO-10;
– T
= (V
= (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
DRAIN
= 12 - 3 x 3.6 = 1.2 V
= 50 °C;
x P
25
25
- V
D
+ T
FB
35
35
A
) x I
P
P
DMAX
DMAX
LED
45
45
+ (V
= (T
= (T
55
55
CC
JMAX
JMAX
x I
-3
A
= 1.1 W
CC
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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