LM2703

Micropower Step-up DC/DC Converter with 350mA Peak

Current Limit

General Description

The LM2703 is a micropower step-up DC/DC in a small

5-lead SOT-23 package. A current limited, fixed off-time

control scheme conserves operating current resulting in high

efficiency over a wide range of load conditions. The 21V

switch allows for output voltages as high as 20V. The low

400ns off-time permits the use of tiny, low profile inductors

and capacitors to minimize footprint and cost in space-

conscious portable applications. The LM2703 is ideal for

LCD panels requiring low current and high efficiency as well

as white LED applications for cellular phone back-lighting.

The LM2703 can drive up to 4 white LEDs from a single

Li-Ion battery.

Features

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350mA, 0.7

Ω, internal switch

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Uses small surface mount components

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Adjustable output voltage up to 20V

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2.2V to 7V input range

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Input undervoltage lockout

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0.01µA shutdown current

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Small 5-Lead SOT-23 package

Applications

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LCD Bias Supplies

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White LED Back-Lighting

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Handheld Devices

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Digital Cameras

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Portable Applications

Typical Application Circuit

20030601

FIGURE 1. Typical 20V Application

April 2003

© 2003 National Semiconductor Corporation

DS200306

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