LT1937
U
TYPICAL APPLICATIO S
Li-Ion to Two White LEDs
Two LED Efficiency
86
84
82
80
78
76
74
72
70
L
D
22µH
V
= 3.6V
IN
V
IN
3V TO 5V
C
C
OUT
IN
1µF
1µF
V
IN
= 3V
V
DC
DIMMING
V
SW
FB
IN
90k
LT1937
5k
SHDN
GND
R1
2Ω
C
C
: TAIYO YUDEN JMK107BJ105
: AVX 0603ZD105
D: CENTRAL CMDSH2-3
L: MURATA LQH3C220
IN
1937 TA05a
20
LED CURRENT (mA)
0
10
30
40
OUT
1937 TA05a
Li-Ion to Three White LEDs
Three LED Efficiency
90
85
L
D
22µH
V
IN
3V TO 5V
C
C
OUT
IN
1µF
0.22µF
V
DC
DIMMING
80
75
V
IN
= 3V
V
IN
= 3.6V
V
SW
FB
IN
90k
LT1937
SHDN
GND
5k
70
65
60
R1
4Ω
C
C
: TAIYO YUDEN JMK107BJ105
: AVX 0603YD224
D: CENTRAL CMDSH-3
L: MURATA LQH3C220
IN
1937 TA01a
0
5
10
LED CURRENT (mA)
15
20
OUT
1937 TA01b
1937f
9
Linear [ Linear ]
