Datasheet

LT3478/LT3478-1
22
34781f
TYPICAL APPLICATIO S
U
LT3478
SHDN
V
REF
PWM
CTRL2
CTRL1
OVPSET
SS V
C
R
T
V
IN
V
S
L OUT LED SW
R1
24k
R
SENSE
0.068Ω
1.5A
R4
365Ω
R
T
69.8k
f
OSC
= 500kHz
100Hz
R2
100k
PWM
DIMMING RATIO = 3000:1
L1: CDRH105R-100
D1: PDS560
Q1: 2N7002
Q2: Si2319DS
LEDs: LXK2 (WHITE)
TYPICAL EFFICIENCY = 90%
FOR CONDITIONS/COMPONENTS SHOWN
(PWM DUTY CYCLE = 100%, T
A
=25°C)
Q2
D1
3478 TA07a
L1
10µH
4 LEDs
3.3V
0V
PV
IN
32V
C1
3.3µF
50V
C3
10µF
25V
C
C
0.1µF
C
SS
1µF
C2
4.7µF
10V
V
IN
3.3V
Q1
R3
10k
R5
510Ω
24W, 4 LEDs at 1.5A, Buck Mode LED Driver