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LTC1515 Series

Step-Up/Step-Down

Switched Capacitor DC/DC

Converters with Reset

Daisy-Chained Control Outputs

FEATURES

The LTC

micropower switched capacitor DC/DC converters that

produce a regulated output voltage by either stepping up

or stepping down the input voltage. Output voltage is

adjustable using an external resistor divider (LTC1515) or

programmable to either 3V/5V (LTC1515-3/5) or 3.3V/5V

(LTC1515-3.3/5) using a logic pin.

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 power-on reset circuit forces the POR pin low

on initial power-up. The POR output remains low until

The parts are short-circuit and overtemperature protected.

Battery life is maximized by very low operating currents

available in an SO-8 package.

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Adjustable/Selectable 3V, 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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Very Low Shutdown Current: < 1

µA

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Short-Circuit and Overtemperature Protected

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650kHz Switching Frequency

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Open-Drain Power-On Reset Output

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Available in SO-8 Package

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SIM Interface in GSM Cellular Telephones

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Smart Card Readers

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Local Power Supplies

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Portable Equipment

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

Programmable 3.3V/5V Power Supply with Power-On Reset

SHDN

POR

GND

5/3

LTC1515-3.3/5

1

2

3

4

8

7

6

5

0.22

µF

10

µF

10

µF

4-CELL

NiCd

100k

ON OFF

RESET

5V 3.3V

LTC1515 • TA01

+

+

LTC1515-X 5V Output vs Input Voltage

INPUT VOLTAGE (V)

2

10

LT1515 • TA02

4

6

8

3

5

7

9

5.2

5.1

5.0

4.9

4.8

5/3 = 3V