Datasheet

12
LT3491
3491fa
TYPICAL APPLICATIO S
U
Li-Ion Driver for One White LED Efficiency
LED
V
IN
C2
1µF
C1
1µF
L1
10µH
C1: TAIYO YUDEN LMK212BJ105MD
C2: TAIYO YUDEN GMK316BJ105ML
L1: MURATA LQH32CN100
V
IN
3V TO 5V
R
SENSE
10Ω
3491 TA07a
LT3491
SHUTDOWN
AND
DIMMING
CONTROL
SW CTRL
CAP
GND
LED CURRENT (mA)
0
10
EFFICIENCY (%)
15
25
30
35
60
V
IN
= 3.6V
45
5
10
3491 TA07b
20
50
55
40
15
20
Li-Ion Driver for Two White LEDs Efficiency
LED
V
IN
C2
1µF
C1
1µF
L1
10µH
C1: TAIYO YUDEN LMK212BJ105MD
C2: TAIYO YUDEN GMK316BJ105ML
L1: MURATA LQH32CN100
V
IN
3V TO 5V
R
SENSE
10Ω
3491 TA08a
LT3491
SHUTDOWN
AND
DIMMING
CONTROL
SW CTRL
CAP
GND
LED CURRENT (mA)
0
EFFICIENCY (%)
50
55
60
20
3491 TA08b
45
40
25
5
10
15
35
30
70
V
IN
= 3.6V
65
2-Cell Li-Ion Driver for Torch and Flash Mode LED Control
Efficiency
CAP LED
D1
V
IN
C2
4.7µF
C1
1µF
L1
10µH
C1: TAIYO YUDEN LMK212BJ105MD
C2: TAIYO YUDEN LMK212BJ475MG
D1: AOT-2015 HPW1751B
L1: MURATA LQH32CN100
V
IN
6V TO 9V
R
SENSE
1Ω
3491 TA09a
LT3491
CTRL SW
GND
V
CTRL
1.5V
V
CTRL
680mV
FLASH MODE
I
LED
= 200mA
TORCH MODE
I
LED
= 100mA
V
IN
(V)
6
80
75
70
65
60
55
50
7.5 8.5
3491 TA09b
6.5 7
89
EFFICIENCY (%)
I
LED
= 100mA