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MAX1561 Datasheet, PDF (4/10 Pages) Maxim Integrated Products – High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs
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High-Efficiency, 26V Step-Up Converters
for Two to Six White LEDs
Typical Operating Characteristics
(Circuit of Figure 1, VIN = 3.6V, ILED = 15mA, L1 = 22µH, CIN = 2.2µF, COUT = 0.1µF, CCOMP = 0.1µF, RSENSE = 7.5Ω, 4 LEDs,
TA = +25°C, unless otherwise noted.)
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. NUMBER of LEDs)
100
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. INPUT VOLTAGE)
100
MAX1561
EFFICIENCY vs. LED CURRENT
(vs. INDUCTANCE)
100
90
6 LEDs
80
70
60
4 LEDs
2 LEDs
90
2.7VIN
80
70
3.6VIN
60
4.2VIN
90
22µH
10µH
80
70
47µH
60
4.7µH
50
50
50
40
0
5
10
15
20
LED CURRENT (mA)
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. NUMBER OF LEDs)
100
90
6 LEDs
40
0
5
10
15
20
LED CURRENT (mA)
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. INPUT VOLTAGE)
100
90
40
0
5
10
15
20
LED CURRENT (mA)
MAX1599 EFFICIENCY vs. LED CURRENT
(vs. INDUCTANCE)
100
47µH
90
80
70
2 LEDs
60
4 LEDs
50
80
70
4.2VIN
60
2.7VIN
50
3.6VIN
80
22µH
70
60
50
40
0
5
10
15
20
LED CURRENT (mA)
40
0
5
10
15
20
LED CURRENT (mA)
40
0
5
10
15
20
LED CURRENT (mA)
INPUT RIPPLE vs. INDUCTANCE
40
INPUT RIPPLE SPECTRUM
6
LED CURRENT vs. DIRECT-PWM
DIMMING DUTY CYCLE
25
35
30
25
20
15
10
5
0
0 5 10 15 20 25 30 35 40 45 50
INDUCTANCE (µH)
5
4
3
2
1
0
0 1 2 3 4 5 6 7 8 9 10
FREQUENCY (MHz)
20
15
10
5
VCTRL = SQUARE WAVE
200Hz < FREQ < 200kHz
0
0 10 20 30 40 50 60 70 80 90 100
DIRECT-PWM DIMMING DUTY CYCLE (%)
4 _______________________________________________________________________________________
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