Datasheet

11
LTC1872
LTC1872 12V/500mA Boost Converter
TYPICAL APPLICATIO
U
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC1872 Three-Cell White LED Driver
I
TH
/RUN
LTC1872
10k
R1
0.033Ω
1.1M
78.7k
L1
10µH
220pF
C1: TAIYO YUDEN CERAMIC EMK325BJ106MNT
C2: AVX TPSE476M016R0150
D1: IR10BQ015
L1: COILTRONICS UP2B-100
M1: Si9804DV
R1: DALE 0.25W
GND
V
FB
5
4
6
1872 TA02
1
2
3
NGATE
V
IN
SENSE
–
C1
10µF
10V
V
IN
3V TO 9.8V
V
OUT
12V
C2
47µF
16V
+
M1
D1
I
TH
/RUN
LTC1872
10k
R1
0.27Ω
53.6Ω
L1
150µH
220pF
C1: TAIYO YUDEN CERAMIC EMK325BJ106MNT
C2: AVX TPSD156M035R0300
D0: MOTOROLA MBR0540
D1-D7: CMD333UWC
GND
V
FB
5
4
6
1872 TA04
1
2
3
NGATE
V
IN
SENSE
–
C1
10µF
10V
V
OUT
≈ 28.8V
(WITH 8 LEDs)
C2
15µF
35V
+
C3
0.1µF
CERAMIC
M1
D0
1 TO 8
WHITE
LEDs
15mA
D1
D2
•
•
•
D8
AA
AA
AA
V
IN
= 3 AA CELLS ≈ 2.7V TO 4.8V
L1: COILCRAFT DO1608C-154
M1: Si9804
R1: DALE 0.25W