CAT4237TD-T3 Datasheet, PDF (6/14 Pages) ON Semiconductor – High Voltage CMOS Boost White LED Driver

CAT4237
TYPICAL CHARACTERISTICS
V_IN = 3.6V, C_IN = 4.7μF, C_OUT = 0.22µF, L = 33µH with 8 LEDs at 20mA, T_AMB = 25ºC, unless otherwise specified.
LED Current vs. Input Voltage (8 LEDS)
LED Current Regulation (20mA)
35
1.0%
30
25
R_FB = 10_Ω
R_FB = 15_Ω
20
15
10
R_FB = 20_Ω
5
0.5%
0.0%
-0.5%
0
2.5 3.0 3.5 4.0 4.5 5.0
INPUT VOLTAGE [V]
-1.0%
3.0 3.3 3.6 3.9 4.2 4.5 4.8
INPUT VOLTAGE [V]
8 LED Efficiency vs. Load Current
90
VIN = 4.2V
85
80
VIN = 3.6V
75
8 LEDs
70 _{VOUT ~ 27V at 20mA}
L = 33uH
65
5
10 15 20 25 30
LED CURRENT [mA]
8 LED Efficiency vs. Input Voltage
90
20mA
85
15mA
80
75
8 LEDs
70
VOUT ~ 27V at 20mA
L = 33uH
65
3.0
3.5
4.0
4.5
5.0
INPUT VOLTAGE [V]
7 LED Efficiency vs. Load Current
90
VIN = 4.2V
85
VIN = 3.6V
80
75
7 LEDs
70 _{VOUT ~ 23V at 20mA}
L = 33uH
65
5
10 15 20 25 30
LED CURRENT [mA]
6 LED Efficiency vs. Load Current
90
VIN = 4.2V
85
VIN = 3.6V
80
75
6 LEDs
70 _{VOUT ~ 20V at 20mA}
L = 33uH
65
5
10 15 20 25 30
LED CURRENT [mA]
Doc. No. MD-5013, Rev. C
6
2008 SCILLC. All rights reserved.
Characteristics subject to change without notice