Datasheet

LT3477
14
3477fc
APPLICATIONS INFORMATION
Figure 9b. PWM Dimming Waveforms
Figure 9a. 10V to 2 White LEDs: Buck-Boost Mode With PWM Dimming
2ms/DIV
I
LED
500mA/DIV
I
L
1A/DIV
PWM
10V/DIV
3477 F09b
V
IN
= 10V
2 LEDs
300mA
PWM FREQUENCY = 100Hz
BUCK-BOOST MODE
1M
1k
1k
C2
10μF
C1
3.3μF
V
IN
10V
300mA
49.9k
L1
4.7μH
D1
I
SN1
I
SP1
V
IN
I
ADJ2
I
ADJ1
FBN
I
SP2
FBP
V
REF
C1: TAIYO YUDEN LMK316BJ335ML
C2: TAIYO YUDEN UDK325BJ106MM
L1: TOKO D53LC (PN# A915AY-4R7M)
D1: ZETEX ZLLS1000
D2: DIODES INC 1N4148
NMOS1, NMOS2: ZETEX 2N7002
PMOS: SILICONIX Si2303BDS
LED1, LED2: LUMILEDS LXHL-BW02
C
C
10nF
C
SS
33nF
3477 F09a
6.81k
NMOS1
100k
0
5V
100Hz
PWM
SW
D2
SS
GND
LT3477
I
SN2
R
T
SHDN
V
C
R
C
1.5k
R
SENSE
0.33Ω
LED2 LED1
PWM
NMOS2
PMOS