CAT4137 Datasheet, PDF (5/16 Pages) Catalyst Semiconductor – CMOS Boost Converter - White LED Driver

CAT4137
TYPICAL CHARACTERISTICS
(V_IN = 3.6 V, C_IN = 1.0 mF, C_OUT = 0.22 mF, L = 22 mH with 3 LEDs at 20 mA, T_AMB = 25°C, unless otherwise specified.)
35
0.4
R_FB = 10 W
30
25
0.2
R_FB = 15 W
20
R_FB = 20 W
0
15
10
5
0
2.0 2.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLTAGE (V)
Figure 8. LED Current vs. Input Voltage
(3 LEDs)
100
−0.2
−0.4
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE (V)
Figure 9. LED Current Regulation
100
90
15 mA
80
20 mA
70
90
VIN = 4.2 V
VIN = 3.6 V
80
70
60
2.0 2.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLTAGE (V)
Figure 10. Efficiency across Supply Voltage
(3 LEDs)
100
60
0
5
10
15
20
25
30
LED CURRENT (mA)
Figure 11. Efficiency across Load Current
(3 LEDs)
100
90
15 mA
80
20 mA
70
90
VIN = 4.2 V
VIN = 3.6 V
80
70
60
2.0 2.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLTAGE (V)
Figure 12. Efficiency across Supply Voltage
(4 LEDs)
60
0
5
10
15
20
25
30
LED CURRENT (mA)
Figure 13. Efficiency across Load Current
(4 LEDs)
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