LT1937
TYPICAL APPLICATIO S
Li-Ion to Five White LEDs
L
22µH
C
IN
1µF
V
IN
3V TO 5V
EFFICIENCY (%)
V
DC
DIMMING
V
IN
LT1937
SHDN
GND
FB
R1
4Ω
SW
90k
5k
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: TAIYO YUDEN GMK212BJ224
D: CENTRAL CMDSH-3
L: MURATA LQH3C220
5V to Seven White LEDs
L
22µH
C
IN
1µF
D
C
OUT
0.22µF
V
IN
5V
EFFICIENCY (%)
V
DC
DIMMING
V
IN
LT1937
SHDN
GND
FB
R1
4Ω
SW
90k
5k
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: TAIYO YUDEN GMK212BJ224
D: CENTRAL CMDSH-3
L: MURATA LQH3C220
10
U
U
D
Five LED Efficiency
85
C
OUT
0.22µF
80
V
IN
= 3V
75
V
IN
= 3.6V
70
1937 TA03a
65
0
2
4
6
8
LOAD CURRENT (mA)
10
12
1937 TA03b
Seven LED Efficiency
85
80
75
70
1937 TA04a
65
0
5
10
LOAD CURRENT (mA)
15
1937 TA04b
1937f