LT1173

1

Micropower

DC/DC Converter

Adjustable and Fixed 5V, 12V

5V/DIV

0V

PROGRAM

5V/DIV

5ms/DIV

1173 TA02

L1*

100

µH

LT1173 • TA01

+

GND

SW2

FB

SW1

LIM

I

IN

V

LT1173

10 F

SANYO

OS-CON

100 F

µ

12V

100mA

1N5818

µ

+

1N4148

PROGRAM

47

Ω

*L1 = GOWANDA GA20-103K

COILTRONICS CTX100-4

NO OVERSHOOT

EFFICIENCY = 81%

Logic Controlled Flash Memory VPP Generator

VPP Output

DESCRIPTIO

S

FEATURE

S

APPLICATI

and LTC are registered trademarks and LT is a trademark of Linear Technology Corporation.

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Operates at Supply Voltages From 2.0V to 30V

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Consumes Only 110

µA Supply Current

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Works in Step-Up or Step-Down Mode

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Only Three External Components Required

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Low Battery Detector Comparator On-Chip

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User-Adjustable Current Limit

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Internal 1A Power Switch

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Fixed or Adjustable Output Voltage Versions

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Space Saving 8-Pin MiniDIP or SO8 Package

The LT1173 is a versatile micropower DC-DC converter.

The device requires only three external components to

deliver a fixed output of 5V or 12V. Supply voltage ranges

from 2.0V to 12V in step-up mode and to 30V in step-down

mode. The LT1173 functions equally well in step-up, step-

down or inverting applications.

The LT1173 consumes just 110

µA supply current at

standby, making it ideal for applications where low quies-

cent current is important. The device can deliver 5V at

80mA from a 3V input in step-up mode or 5V at 200mA

from a 12V input in step-down mode.

Switch current limit can be programmed with a single

resistor. An auxiliary gain block can be configured as a low

battery detector, linear post regulator, under voltage lock-

out circuit or error amplifier.

For input sources of less than 2V, use the LT1073.

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Flash Memory Vpp Generators

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3V to 5V, 5V to 12V Converters

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9V to 5V, 12V to 5V Converters

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LCD Bias Generators

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Peripherals and Add-On Cards

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Battery Backup Supplies

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Laptop and Palmtop Computers

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Cellular Telephones

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Portable Instruments

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APPLICATI

TYPICAL