LTC3454

1

3454fa

TYPICAL APPLICATION

DESCRIPTION

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

All other trademarks are the property of their respective owners.

FEATURES

APPLICATIONS

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.

>80% in Flash Mode

× 3mm)

DFN Package

High Efficiency Torch/Flash LED Driver

LED

20.5k

1%

3454 TA01a

3.65k

1%

EN2 (FLASH)

EN1 (TORCH)

EN2 EN1

0

0

0 (SHUTDOWN)

0

1

150mA

1

0

850mA

11

1A

0.1μF

GND (EXPOSED PAD)

LTC3454

LED: LUMILEDS LXL-PWF1

L1: SUMIDA CDRH6D28-5RONC

SW1

A

B

D

C

SW2

10μF

2.7V TO 4.2V

1-CELL Li-Ion

10μF

L1

5μH

1MHz

BUCK-BOOST

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