LP3988

Micropower, 150mA Ultra Low-Dropout CMOS Voltage

Regulator With Power Good

General Description

The LP3988 is a 150mA low dropout regulator designed

specially

to

meet

requirements

of

Portable

battery-

applications. The LP3988 is designed to work with a space

saving, small 1µF ceramic capacitor. The LP3988 features

an Error Flag output that indicates a faulty output condition.

The LP3988’s performance is optimized for battery powered

systems to deliver low noise, extremely low dropout voltage

and low quiescent current. Regulator ground current in-

creases only slightly in dropout, further prolonging the bat-

tery life.

Power supply rejection is better than 60 dB at low frequen-

cies and starts to roll off at 10 kHz. High power supply

rejection is maintained down to lower input voltage levels

common to battery operated circuits.

The device is ideal for mobile phone and similar battery

powered wireless applications. It provides up to 150 mA,

from a 2.5V to 6V input, consuming less than 1 µA in disable

mode and has fast turn-on time less than 200µs.

The LP3988 is available 5 pin SOT-23 package and 5 bump

thin micro SMD package. Performance is specified for −40˚C

to +125˚C temperature range and is available in 1.85, 2.5,

2.6, 2.85, 3.0 and 3.3V output voltages.

Key Specifications

n

2.5 to 6.0V input range

n

150mA guaranteed output

n

40dB PSRR at 10kHz

n

≤1 µA quiescent current when shut down

n

Fast Turn-On time: 100 µs (typ.)

n

80 mV typ dropout with 150mA load

n

−40 to +125˚C junction temperature range for operation

n

1.85V, 2.5V, 2.6V, 2.85V, 3.0V, and 3.3V

Features

n

5 bump thin micro SMD package

n

SOT-23-5 package

n

Power-good flag output

n

Logic controlled enable

n

Stable with ceramic and high quality tantalum capacitors

n

Fast turn-on

n

Thermal shutdown and short-circuit current limit

Applications

n

CDMA cellular handsets

n

Wideband CDMA cellular handsets

n

GSM cellular handsets

n

Portable information appliances

n

Typical Application Circuit

20020502

August 2004

© 2004 National Semiconductor Corporation

DS200205

www.national.com