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LTC1574

LTC1574-3.3/LTC1574-5

High Efficiency Step-Down

DC/DC Converters

with Internal Schottky Diode

The LTC

DC/DC converters ideally suited for 9V to 5V, 5V to 3.3V

and inverting operation. With an internal 0.9

Ω switch (at

a supply voltage of 12V) and a low forward drop Schottky

requires only three external components to construct a

complete high efficiency DC/DC converter.

Under no load condition, the LTC1574 draws only 130

µA.

In shutdown, it draws a mere 2

µA making this converter

ideal for battery-powered applications. In dropout, the

internal P-channel MOSFET switch is turned on continu-

ously allowing the user to maximize the life of the battery

source.

The maximum inductor current of the LTC1574 family is

pin selectable to either 340mA or 600mA, optimizing

efficiency for a wide range of applications. Operation up to

200kHz permits the use of small surface mount inductors

and capacitors.

For applications requiring higher output current or ultra-

high efficiency, see the LTC1148 and LTC1265 data sheets.

For detailed applications information, see the LTC1174

data sheet.

FEATURES

High Efficiency Step-Down Converter

+

100

22

µF*

35V

+

100

µF*

10V

1574 TA01

5V

175mA

5

2, 4, 13, 15

7

10

3, 14

12

11

6

5.5V to

16V

GND

LTC1574-5

SHDN

SW

* AVX TPSD226K035

** AVX TPSD107K010

LTC1574-5 Efficiency

LOAD CURRENT (mA)

1

100

95

90

85

80

75

70

10

100

1574 TA02

200

L = 100

µH

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

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Inverting Converters

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Step-Down Converters

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Memory Backup Supply

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Portable Instruments

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Battery-Powered Equipment

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Distributed Power Systems

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High Efficiency: Up to 94%

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Usable in Noise-Sensitive Products

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Peak Inductor Current Independent of Inductor Value

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Short-Circuit Protection

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Internal Low Forward Drop Schottky Diode

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Only Three External Components Required

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Low Dropout Operation

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Low-Battery Detector

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Pin Selectable Current Limit

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Internal 0.9

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Standby Current: 130

µA

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Active Low Micropower Shutdown