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LT1175

500mA Negative

Low Dropout Micropower

Regulator

The LT

lator. It features 45

µA quiescent current, dropping to

10

µA in shutdown. A new reference amplifier topology

gives precision DC characteristics along with the ability to

maintain good loop stability with an extremely wide range

of output capacitors. Very low dropout voltage and high

efficiency are obtained with a unique power transistor anti-

saturation design. Adjustable and fixed 5V versions are

available.

Several new features make the LT1175 very user-friendly.

The SHDN pin can interface directly to either positive or

negative logic levels. Current limit is user-selectable at

200mA, 400mA, 600mA and 800mA. The output can be

forced to reverse voltage without damage or latchup.

Unlike some earlier designs, the increase in quiescent

current during a dropout condition is actively limited.

The LT1175 has complete blowout protection with current

limiting, power limiting and thermal shutdown. Special

attention was given to the problem of high temperature

operation with micropower operating currents, preventing

output voltage rise under no-load conditions. The LT1175

is available in 8-pin PDIP and SO packages, 3-lead SOT-

223 as well as 5-pin surface mount DD and through-hole

TO-220 packages. The 8-pin SO package is specially

constructed for low thermal resistance.

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Stable with Wide Range of Output Capacitors

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Operating Current: 45

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Shutdown Current: 10

µA

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Adjustable Current Limit

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Positive or Negative Shutdown Logic

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Low Voltage Linear Dropout Characteristics

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Fixed 5V and Adjustable Versions

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Tolerates Reverse Output Voltage

OUTPUT CURRENT (A)

0

1.0

0.8

0.6

0.4

0.2

0

0.2

0.4

0.5

1175 TA02

0.1

0.3

0.6

0.7

Minimum Input-to-Output Voltage

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Analog Systems

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Modems

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Instrumentation

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A/D and D/A Converters

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Interface Drivers

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Battery-Powered Systems

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

Typical LT1175 Connection

INPUT SUPPLY CAPACITOR. SEE APPLICATIONS INFORMATION

SECTION FOR DETAILS

≥ 0.1µF

–5V

UP TO 500mA

SHDN

GND

LT1175-5

SENSE

OUT

1175 TA01

INPUT

+

+

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO