LTC3215

1

3215f

TYPICAL APPLICATIO

APPLICATIO S

FEATURES

DESCRIPTIO

PDAs and Digital Cameras

■

High Efficiency Operation: 1x, 1.5x or 2x Boost

Modes with Automatic Mode Switching

■

Output Current up to 700mA

■

Open/Shorted LED Protection

■

4% LED Current Programming Accuracy

■

Tiny Application Circuit (All Components <1mm

Profile)

700mA Low Noise High

Current LED Charge Pump

The LTC

DC/DC converter designed to power high current LEDs.

The part includes an accurate programmable current

source capable of driving loads up to 700mA from a 2.9V

to 4.4V input. Low external parts count (two flying capaci-

tors, one programming resistor and two bypass capaci-

tors) makes the LTC3215 ideally suited for small, battery-

powered applications.

Built-in soft-start circuitry prevents excessive inrush cur-

rent during start-up. High switching frequency enables the

use of small external capacitors. LED current is pro-

grammed with an external resistor. The LED is discon-

An ultralow dropout current source maintains accurate

switching optimizes efficiency by monitoring the voltage

across the LED current source and switching modes only

a low profile 3mm × 3mm 10-Lead DFN package.

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

C1

2.2µF

C2

2.2µF

2.2µF

4.7µF

200mA

LED1

2.9V TO 4.4V

EN

DISABLE ENABLE

LTC3215

3215 TA01a

LED1: AOT2015 HPW 1751B

CPO

20k

1%

2.8

100

90

80

70

60

50

40

30

20

10

0

3.2

3.6

3.8

3215 TA01b

3.0

3.4

4.0

4.2

4.4

LED = AOT2015 HPW 1751B

*Protected by U.S. Patent 6411531.