Datasheet

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