Product Summary

The 3551S is a fixed frequency, current mode step-up DC/DC converter with two integrated NFETs that can be used for precision LED brightness control. The devices are capable of driving loads up to 1A from a single-cell Li-Ion battery. The 3551S is suitable for (1)White LED Camera Flash; (2)White LED Torch (Flashlight); (3)DSC (Digital Still Camera) Flash; (4)Cellular Camera Phone Flash; (5)PDA Camera Flash; (6)Camcorder Torch (Flashlight) lamp.

Parametrics

3551S absolute maximum ratings: (1)VIN pin: Voltage to GND 7.5V; (2)SW pin: Voltage to GND 21V; (3)FB pin: Voltage to GND 7V; (4)VC pin: Voltage to GND 1.26V ± 0.3V; (5)SD,T/F pins: Voltage to GND 7.5V; (6)FET-T, FET-F: Voltage to GND 6V; (7)Junction Temperature (TJ-MAX )150℃; (8)Storage Temperature Range -65 to +150℃; (9)ESD Rating: 2.0kV.

Features

3551S features: (1)Up to 1A total drive current; (2)Flash timeout protection; (3)Independent Torch/Flash/Shutdown modes; (4)LED disconnect in shutdown; (5)Programmable soft-start limits inrush current; (6)Over-voltage protection; (7)Wide voltage range 2.7 to 5.5V; (8)1.25MHz constant switching frequency; (9)Small, low profile package, non-pullback LLP14 (4mm×4mm).

Diagrams

3551S block diagram

3551
3551
Keystone Electronics
Fuseholders, Clips, & Hardware .187X.032 F PCB TERM
Data Sheet
0-1: $0.13
1-100: $0.08
100-500: $0.06
500-1000: $0.05
35510
35510
Menda
Liquid Dispensers & Bottles 8oz Pure Touch Disp Pump Nat HDPE Sq.
Data Sheet
0-1: $11.99
1-10: $11.39
10-25: $10.83
25-50: $10.28
35511
35511

SLEEVE DISS PURE-TOUCH 8OZ
Data Sheet
Negotiable 
3551-1
3551-1
Cooper Bussmann
Circuit Breakers BUSS FUSEBLOCK
Data Sheet
0-1: $13.03
1-5: $12.37
5-10: $12.05
10-25: $11.73
3551-1BS
3551-1BS
Cooper Bussmann
Circuit Breakers BUSS FUSEBLOCK
Data Sheet
Negotiable 
35512-0200
35512-0200
Molex
Headers & Wire Housings STSL BULB SOCKET REC LB SOCKET RECPT 2CKT
Data Sheet
0-1: $0.37
1-10: $0.34
10-100: $0.27
100-500: $0.22