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LTC1514-3.3/LTC1514-5

Step-Up/Step-Down Switched

Capacitor DC/DC Converters

with Low-Battery Comparator

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3.3V or 5V Output Voltages

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2V to 10V Input Voltage Range

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Up to 50mA Output Current

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Only Three External Capacitors Required

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Soft Start Limits Inrush Current at Turn-On

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Low Operating Current: 60

µA

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Low Shutdown Current: 10

µA

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Short-Circuit and Overtemperature Protected

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650kHz Switching Frequency

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Low-Battery Comparator Active in Shutdown

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Available in SO-8 Package

FEATURES

The LTC

capacitor DC/DC converters that produce a regulated

output voltage by either stepping up or stepping down

the input voltage. Output voltage is fixed at either 3.3V

(LTC1514-3.3) or 5V (LTC1514-5) by an internal resistor

divider.

A unique architecture allows the parts to accommodate

a wide input voltage range (2V to 10V) while maintaining

±4% regulation. Additional circuitry prevents excessive

An internal uncommitted comparator is kept active in

shutdown. The comparator has an open-drain output for

flexible interfacing.

The parts are short-circuit and overtemperature pro-

tected. Battery life is maximized by very low operating

are available in an SO-8 package.

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

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Battery-Operated Equipment

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Smart Card Readers

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Local Power Supplies

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Handheld Instruments

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Battery Backup Supplies

INPUT VOLTAGE (V)

2

10

LT1514 • TA02

4

6

8

3

5

7

9

5.2

5.1

5.0

4.9

4.8

1

2

3

4

8

7

6

5

SHDN

LBO

LBI

GND

LTC1514-5

100k

0.22

µF

10

µF

10

µF

4-CELL

NiCd

1.33M

1%

499k

1%

ON OFF

LOW BAT

1514 TA01

+

+

5V Step-Up/Step-Down Power Supply with Low-Battery Detect

LTC1514-5 Output Voltage

vs Input Voltage