LP3986

Dual Micropower 150 mA Ultra Low-Dropout CMOS

Voltage Regulators in micro SMD Package

General Description

The LP3986 is a 150 mA dual low dropout regulator de-

signed for portable and wireless applications with demand-

ing performance and board space requirements.

capacitor requiring smallest possible board space.

The LP3986’s performance is optimized for battery powered

systems to deliver ultra low noise, extremely low dropout

voltage and low quiescent current independent of load cur-

rent. Regulator ground current increases very slightly in

dropout, further prolonging the battery life. Optional external

bypass capacitor reduces the output noise further without

slowing down the load transient response. Fast start-up time

is achieved by utilizing a speed-up circuit that actively pre-

charges the bypass capacitor. Power supply rejection is

better than 60 dB at low frequencies and 55 dB at 10 kHz.

High power supply rejection is maintained at low input volt-

age levels common to battery operated circuits.

The LP3986 is available in a micro SMD package. Perfor-

mance is specified for a −40˚C to +125˚C temperature

range. For single LDO applications, please refer to the

LP3985 datasheet.

Features

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Miniature 8-I/O micro SMD package

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Stable with 1µF ceramic and high quality tantalum

output capacitors

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Fast turn-on

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Two independent regulators

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Logic controlled enable

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Over current and thermal protection

Key Specifications

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Guaranteed 150 mA output current per regulator

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1nA typical quiescent current when both regulators in

shutdown mode

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60 mV typical dropout voltage at 150 mA output current

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115 µA typical ground current

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40 µV typical output noise

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200 µs fast turn-on circuit

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−40˚C to +125˚C junction temperature

Applications

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CDMA cellular handsets

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GSM cellular handsets

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Portable information appliances

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Portable battery applications

Typical Application Circuit

20003401

May 2003

© 2003 National Semiconductor Corporation

DS200034

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