Datasheet

17
LT1307/LT1307B
1307fa
Single Cell Powered Constant Current LED Driver
C1
1µF
CERAMIC
L1
10µH
D1
V
IN
1307 TA05
NC
D2
40mA
R1
5.1Ω
100k
ON/OFF
V
IN
R2
22k
100k
C2
1µF
CERAMIC
Q1
2N3906
AA
CELL
C3
22µF
L1: MURATA-ERIE LQH3C100K04
D1: 1N4148
C1, C2: CERAMIC
D2, D3: LUMEX SSL-X100133SRC/4 "MEGA-BRITE" RED LED
OR PANASONIC LNG992CF9 HIGH BRIGHTNESS BLUE LED
+
V
IN
SW
FB
LT1307B
LBI
LBO
SHDN
V
C
GND
Flash Memory VPP Supply
V
IN
SW
FB
LT1307
L1
10µH
D1
47k
232k
1%
2M
1%
1307 TA09
0.33µF
CERAMIC
×2
12V/30mA FROM 3V
12V/60mA FROM 5V
~250mV
P-P
RIPPLE
0.33µF
V
C
GND
SHDNSHUTDOWN
D1: MOTOROLA MBR0520L
L1: MURATA-ERIE LQH3C100K04
1µF
TANTALUM
2000pF
1N4148
V
IN
3V TO 5.5V
10pF
+
High Voltage Flyback Converter
V
IN
V
IN
1V TO 5V
SW
1N4148
4
6
3
1
•
•
LT1307
FBSHDNSHUTDOWN
V
C
100k
1000pF
GND
R2
240k
1%
R1
2V
OUT
V
OUT
0.1µF
1µF
CERAMIC
0.01µF
0.1µF
1307 TA06
OPTIONAL
DOUBLER
T1
1:12
T1: DALE LPE3325-A190, n = 12 [phone]
MAXIMUM DUTY CYCLE: ≈80%
FOR FLYBACK, V
OUT
= n(V
IN
– V
SW
)
V
OUT
= 1.22V 1 +
()
R1
R2
DC
1 – DC
FOR 1V
IN
, MAXIMUM V
OUT
=
FOR 2V
IN
, MAXIMUM V
OUT
≈ 85V.
HIGHER VOLTAGES ACHIEVED WITH CAPACITIVE DOUBLER OR TRIPLER
NO SNUBBER REQUIRED WITH SPECIFIED TRANSFORMER AND V
IN
< 5V
12(1 – 0.2) ≈ 37V
0.8
1 – 0.8
TYPICAL APPLICATIO S
U