CAT4238_16 Datasheet, PDF (6/12 Pages) ON Semiconductor – High Efficiency 10 LED Boost Converter

CAT4238
TYPICAL CHARACTERISTICS
(V_IN = 3.6 V, C_IN = 4.7 mF, C_OUT = 0.22 mF, L = 47 mH with 10 LEDs at 20 mA, T_AMB = 25°C, unless otherwise specified.)
40
1.0
35
R1 = 10 W
VOUT = 33.8 V
30
0.5
25
R1 = 15 W
VOUT = 33 V
20
0
15
R1 = 20 W
10
VOUT = 32.5 V
5
0
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
Figure 10. LED Current vs. Input Voltage
−0.5
10 LEDs @ 10 mA
−1.0
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
Figure 11. LED Current Regulation (10 mA)
100
100
90
VIN = 5 V
80
VIN = 3.6 V
70
90
VOUT = 32.5 V
10 LEDs @ 15 mA
80
VOUT = 33 V
10 LEDs @ 20 mA
70
60
5
10
15
20
25
30
LED CURRENT (mA)
Figure 12. Efficiency vs. Load Current
(10 LEDs)
60
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
Figure 13. Efficiency vs. Input Voltage
(10 LEDs)
2.0
1.5
1.0
Figure 14. Power−up with 10 LEDs at 20 mA
0.5
0
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
Figure 15. Switch ON Resistance vs. Input
Voltage
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