Datasheet

LT3476
11
3476fb
typicAl ApplicAtions
5V to 25V Buck-Boost Mode Driver for 2 Series 350mA LEDs
2.2µF
2.2nF
44.2k
600kHz
REF
CAP1-4
SW4
1.05V
SW1
CAP1
300mΩ
LED1
D1 D2 D3 D4
350mA
SW2 SW3
VC1-4
VADJ1-4
LED1-4
V
IN
PWM1-4
PWM1-4
RT
V
IN
3.3V
PV
IN
5V TO 25V
GNDSHDN
LT3476
3476 TA03
SHDN
L1
10µH
2.2µF
CAP2 CAP3 CAP4
300mΩ 300mΩ 300mΩ
LED2 LED3 LED4
350mA
350mA 350mA
L2
10µH
2.2µF 2.2µF 2.2µF
4.99k
L3
10µH
L4
10µH
L1 TO L4: COOPER COILTRONICS MPI4040R3-100R
D1 TO D4: NXP PMEG4010
LED CURRENT (mA)
50
EFFICIENCY (%)
75
65
80
350300
3476 TA03b
70
60
150100
200 250
90
85
PV
IN
= 5V
PV
IN
= 10V
V
IN
= 3.3V
2 WHITE LEDS
V
F
= 3.6V AT 1A
Buck-Boost Mode Efficiency vs LED Current
Buck Mode 100W Quad 1A × 8 LED Driver
L1
10µH
L1 TO L4: TOKO A916CY-100M
D1 TO D4: DIODES, INC. DFLS140
L2
10µH
L3
10µH
L4
10µH
2.2µF
1nF
21k
REF
CAP1-4
SW4
1.05V
SW1
CAP1
100mΩ
LED1
1A
SW2 SW3
VC1-4
VADJ1-4
LED1-4
V
IN
PWM1-4
PWM1-4
RT
0.22µF
D1 D2 D3 D4
0.22µF
UP TO
8 LEDS
V
IN
2.8V TO 16V
PV
IN
33V
CAP2
100mΩ
LED2
GNDSHDN
LT3476
3476 TA05
SHDN
100k
2.2µF
× 4
4.99k
0.22µF 0.22µF
1A 1A 1A
CAP3
100mΩ
LED3
CAP4
100mΩ
LED4
LED CURRENT (A)
0
EFFICIENCY (%)
88
92
1.0
3476 TA05b
84
80
0.40.2
0.6 0.8
100
96
7 LEDS
5 LEDS
V
IN
= 3.3V
PV
IN
= 33V
WHITE LEDS
V
F
= 3.6V AT 1A
Efficiency vs LED Current for Buck Mode