Datasheet

LTC3442
17
3442fa
LED CURRENT (A)
0.1
EFFICIENCY (%)
1.0
3442 TA04b
80
84
88
92
96
82
86
90
94
98
100
V
IN
= 3.6V
750kHz
SW1
V
IN
SHDN/SS
R
LIM
R
T
SGND
SW2
V
OUT
FB
V
C
BURST
PGND
LTC3442
V
IN
2.5V TO
4.2V
LHXL-PW03
4.7µF
V
OUT
1nF
3442 TA04a
3.3µH
47pF
10µF
R5
7.87k
*OFF ON
OPEN LED VOLTAGE LIMIT = (R4+R5)*0.95/R4
* NOTE: THE SHDN/SS VOLTAGE MUST BE NO MORE THAN 0.5V BELOW
V
IN
WHEN ENABLED.
R2 = R1/1.5
I
LED
= 24 • (R1+R2+R3)/(R1 • R3) AMPS
R3
95.3k
R2
200k
R1
301k
57.6k
R4
2k
I
LED
= 500mA
TYPICAL APPLICATIO S
U
High Efficiency Li-Ion Powered Constant Current LED Driver
with Open-LED Protection
LED Driver Efficiency vs LED Current