LP3928

High Speed Bi-Directional Level Shifter and Ultra

Low-Dropout CMOS Voltage Regulator

General Description

The LP3928 is designed for portable and wireless applica-

tions with demanding performance and space requirements.

The LP3928 provides level shifting and power conversion

needed for applications interfacing differing voltage levels.

The part contains a bi-directional level shifter for three sig-

nals to translate the levels between 1.8V and 2.85V and an

ultra low-dropout CMOS 2.85V voltage regulator.

The three level shifted signals are individually direction con-

trolled. Signals going from 2.85V to 1.8V can also be latched

using an external clock source. The latches are powered

from internal 2.85V. There is also an option to by-pass the

latches.

The built-in low-dropout voltage regulator is ideal for mobile

phone and battery powered wireless applications. It provides

up to 150 mA from a 3.05V to 6.0V input, and is character-

ized by extremely low dropout voltage, low quiescent current

and low output noise voltage. It is stable with small 1.5 µF

requiring smallest possible PC board area.

A shutdown mode is available for the level shifters and the

regulator. High performance is achieved over various load

conditions with very low rise and fall times.

Key Specifications

Level Shifter:

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4 ns propagation delay (typ.)

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2 ns rise and fall times (typ.)

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20 ns direction switch response time

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2 µA input/output leakage current

Low-Dropout Regulator:

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3.05V to 6.0V input range

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150 mA guaranteed output

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Fast Turn-On time: 200 µs (typ.)

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100 mV maximum dropout with 150 mA load

Features

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Ultra small micro SMD package

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Bi-directional level-shifter for three individual signals:

1.8V to 2.85V and 2.85V to 1.8V signal level translation

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Logic controlled enable pins: 4 different operation

modes

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LDO stable with ceramic and high quality tantalum

capacitors

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Thermal shutdown

Applications

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Multi-Media Cards for Cellular Phones

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SD Cards for Cellular Handsets

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Logic Level Translation

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Portable Information Appliances

October 2002

© 2002 National Semiconductor Corporation

DS200391

www.national.com