LT1129/LT1129-3.3/LT1129-5

1

112935ff

TYPICAL APPLICATION

DESCRIPTION

Micropower Low Dropout

Regulators with Shutdown

The LT

dropout regulators with shutdown. The devices are capable

of supplying 700mA of output current with a dropout

voltage of 400mV at maximum output. Designed for use

in battery-powered systems, the low quiescent current,

50μA operating and 16μA in shutdown, make them an ideal

choice. The quiescent current does not rise in dropout as

it does with many other low dropout PNP regulators.

Other features of the LT1129 /LT1129-3.3/LT1129-5 include

the ability to operate with small output capacitors. They

are stable with only 3.3μF on the output while most older

devices require between 10μF and 100μF for stability. Also

the input may be connected to ground or a reverse voltage

without reverse current flow from output to input. This

makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup

power situations where the output is held high and the

input is at ground or reversed. Under these conditions,

only 16μA will flow from the output pin to ground. The

devices are available in 5-lead TO-220, 5-lead DD-Pak and

3-lead SOT-223 packages.

FEATURES

APPLICATIONS

5V Supply with Shutdown

IN

OUT

LT1129-5

GND

5V OUT

500mA

3.3μF

SOLID TANTALUM

+

SENSE

112935 TA01

< 0.25

> 2.8

NC

OUTPUT

OFF

ON

ON

SHDN

1

2

3

4

5

OUTPUT CURRENT (A)

0

0.4

0.5

0.6

0.3

0.5

0.3

0.2

0.1

0.2

0.4

0.6

0.7

0.1

0

112935 TA02

Dropout Voltage

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