LP3994

50mA CMOS Voltage Regulator with Enable Control

General Description

The LP3994 regulator provides 1.5V and 1.8V outputs op-

tions at up to 50mA load current. The LP3994 provides an

accurate output voltage with low quiescent current at full

current. Good noise performance is obtained without a noise

bypass capacitor. The low quiescent current in operation can

be reduced to virtually zero when the device is disabled via

a logic signal to the enable input. In conjuction with small

space saving capacitors, the small package size of the mi-

croSMD devices results in a regulator solution with a very

small footprint for any given application.

The LP3994 is suitable for general use within the range of

portable, battery-powered equipment and voltage options

other than 1.5V and 1.8V can be made available.

The LP3994 also features short-circuit and thermal-

shutdown protection.

Performance is specified for a -40˚C to 125˚C temperature

range.

This device is available with output voltages of 1.5V and

1.8V in both microSMD and LLP packages. Other voltages

and alternative packages may be made available, please

contact your local NSC sales office.

Features

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4 Pin MicroSMD Package/ 6 Pin LLP

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No Noise Bypass Capacitor Required

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Logic Controlled Enable

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Stable with Low ESR Ceramic Capacitors

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Fast turn on time

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Thermal-Overload and Short Circuit Protection

Key Specifications

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Input Voltage Range

2.5 to 5.5V

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Output Voltage Range

1.5 to 3.3V

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Output Current

50mA

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Noise Figure

95µV

RMS

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PSRR

70dB

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Fast Startup

10µs

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Output Capacitor

1µF Low ESR

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Virtually Zero I

0.001µA

Package

Tiny 4 Pin micro SMD

1mm by 1mm by 0.6m

6 pin LLP

SOT23 footprint

Applications

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Bluetooth Devices

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Battery Powered Devices

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Portable Information Appliances

Typical Application Circuit

20046501

August 2004

© 2004 National Semiconductor Corporation

DS200465

www.national.com