LT3477EUF#TRPBF Linear Technology, LT3477EUF#TRPBF Datasheet - Page 14

• Manufacturer Part Number: LT3477EUF#TRPBF
• Description: IC LED DRVR HP CONST CURR 20-QFN
• Manufacturer: Linear Technology
• Type: High Power, Constant Currentr

Specifications of LT3477EUF#TRPBF

• Constant Current: Yes
• Constant Voltage: Yes
• Topology: Flyback, PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: General Purpose
• Type - Secondary: White LED
• Frequency: 200kHz ~ 3.5MHz
• Voltage - Supply: 2.5 V ~ 25 V
• Mounting Type: Surface Mount
• Package / Case: 20-QFN
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 3A
• Internal Switch(s): Yes
• Efficiency: 93%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -

LT3477
APPLICATIONS INFORMATION
14
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
5V
0
Figure 9a. 10V to 2 White LEDs: Buck-Boost Mode With PWM Dimming
100Hz
500mA/DIV
PWM
10V/DIV
1A/DIV
PWM
I
10V
LED
V
I
IN
100k
L
D2
V
2 LEDs
300mA
Figure 9b. PWM Dimming Waveforms
IN
= 10V
C1
3.3μF
C
33nF
SS
PWM FREQUENCY = 100Hz
BUCK-BOOST MODE
NMOS1
R
1.5k
C
C
10nF
C
SS
V
I
I
I
SHDN
V
PMOS
ADJ1
ADJ2
SP1
2ms/DIV
IN
C
I
SN1
LT3477
GND
4.7μH
L1
1k
1k
SW
NMOS2
3477 F09b
3477 F09a
V
I
I
FBN
FBP
SN2
REF
SP2
R
D1
T
6.81k
LED2
PWM
1M
49.9k
300mA
LED1
R
0.33Ω
SENSE
C2
10μF
3477fc