LTC3454

1

3454f

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

GND (EXPOSED PAD)

LED

EN2 (FLASH)

EN1 (TORCH)

EN2 EN1

0

0

0 (SHUTDOWN)

0

1

150mA

1

0

850mA

11

1A

0.1

mF

LED: LUMILEDS LXL-PWF1

L1: SUMIDA CDRH6D28-5RONC

20.5k

1%

SW1

A

B

D

C

SW2

1- CELL

Li-Ion

2.7V-4.2V

LTC3454

1MHz

BUCK-BOOST

10

mF

10

mF

L1

5

mH

3453 TA01a

3.65k

1%

LED

2.7

75

80

85

4.3

5.5

5.1

3454 TA01b

70

65

60

3.1

3.9

3.5

4.7

90

95

100

1A Synchronous Buck-Boost

High Current LED Driver

converter optimized for driving a single high power LED

at currents up to 1A from a single cell Li-Ion battery in-

put. The regulator operates in either synchronous buck,

synchronous boost, or buck-boost mode depending on

greater than 90% can be achieved over the entire usable

range of a Li-Ion battery (2.7V to 4.2V).

LED current is programmable to one of four levels, includ-

ing shutdown, with dual external resistors and dual enable

inputs. In shutdown no supply current is drawn.

A high constant operating frequency of 1MHz allows the

use of small external components. The LTC3454 is offered

in a low profile (0.75mm) thermally enhanced 10-lead

(3mm × 3mm) DFN package.

■

Cell Phone Camera Flash

■

Cell Phone Torch Lighting

■

Digital Cameras

■

PDAs

■

Misc Li-Ion LED Drivers

■

High Efficiency: >90% Typical in Torch Mode,

>80% in Flash Mode

■

■

Up to 1A Continuous Output Current

■

3.5% LED Current Programming Accuracy

■

Internal Soft-Start

■

Open/Shorted LED Protection

■

Constant Frequency 1MHz Operation

■

Zero Shutdown Current

■

Overtemperature Protection

■

Small Thermally Enhanced 10-Lead (3mm × 3mm)

DFN Package

High Efficiency Torch/Flash LED Driver

, LTC and LT are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.