1

LT1303/LT1303-5

Micropower High Efficiency

DC/DC Converters with

Low-Battery Detector

Adjustable and Fixed 5V

FEATURES

s

5V at 200mA from a 2V Input

s

Supply Voltage As Low As 1.8V

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Up to 88% Efficiency

s

120

s

Low-Battery Detector

s

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Uses Inexpensive Surface Mount Inductors

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8-Lead PDIP or SO Package

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EL Panel Drivers

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2-Cell and 3-Cell to 5V Conversion

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Palmtop Computers

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Portable Instruments

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Bar-Code Scanners

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PDAs

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Wireless Systems

The LT

efficiency DC/DC converters using Burst Mode

tion. They are ideal for use in small, low-voltage battery-

operated systems. The LT1303-5 accepts an input voltage

between 1.8V and 5V and converts it to a regulated 5V. The

LT1303 is an adjustable version that can supply an output

voltage up to 25V. Quiescent current is only 120

µA from

the battery and the shutdown pin further reduces current

to 10

µA. The low-battery detector provides an open-

collector output that goes low when the input voltage

drops below a preset level. The on-chip NPN power switch

has a low 170mV saturation voltage at a switch current

of 1A. The LT1303/LT1303-5 are available in 8-lead PDIP

or SO packages, easing board space requirements.

For higher output current, please see the LT1305 or

LT1302.

LOAD CURRENT (mA)

0.1

30

70

80

90

1

100

10

1000

LT1303 TA01

60

50

40

5V Output Efficiency

SW

GND

PGND

SENSE

LBI

LBO

SHDN

LT1303-5

+

+

100k

100

µF

SHUTDOWN

412k

1%

100

µF

2 CELLS

316k

1%

L1

22

µH

1N5817

200mA

LOW BATTERY

GOES LOW AT

L1 = SUMDIA CD54-220

LT1303 TA02

Figure 1. 2-Cell to 5V DC/DC Converter with Low-Battery Detect

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

Burst Mode is a trademark of Linear Technology Corporation.