
LT3486
TYPICAL APPLICATIONS
5V to 16/16 White LEDs
D5
5V
D6
C3
1μF
D3
C IN
1μF
D4
C4
1μF
16 LEDs
C1
0.1μF
L1
15μH
L2
15μH
C2
0.1μF
16 LEDs
C OUT1
2.2μF
D1
SW1
V IN
SW2
D2
C OUT2
2.2μF
OVP1
OVP2
25mA
V IN
OFF ON
CTRL1
SHDN
PWM1
LT3486
CTRL2
REF
PWM2
V IN
C REF
0.1μF
25mA
FB1
FB2
V C1
R T
V C2
PWM FREQ
200Hz
Q1
4.02k
4.7nF
63.4k
22pF
4.02k
4.7nF
Q2
PWM FREQ
200Hz
100k
8.06
C IN : 6.3V, X5R OR X7R
C OUT1 , C OUT2 : 35V, X5R OR X7R
C1-C4: 50V, X5R OR X7R
C REF : 6.3V, X5R OR X7R
8.06
D1, D2: ZETEX ZLLS400
D3-D6: PHILIPS BAV99W
L1, L2: TOKO D53LC (TYPE A)
Q1, Q2: FAIRCHILD 2N7002
3486 TA08a
100k
LED Current and Efficiency vs PWM Duty Cycle
PWM Dimming Waveforms
85
80
75
70
V IN = 5V
16/16 LEDs
EFFICIENCY
35
30
25
20
I LED
50mA/DIV
I L
500mA/DIV
65
60
55
LED CURRENT
15
10
5
PWM
5V/DIV
L = 15μH
PWM FREQ = 200Hz
1ms/DIV
3486 TA08c
50
0
20
40
60
80
0
100
PWM DUTY CYCLE (%)
3486 TA08b
3486fe
17