BYPASS

LP3985

IN

OUT

EN

3(A1)

5(C1)

4(A3)

2(B2)

1µF

1(C3)

*

1µF

Pin Numbers in parenthesis indicate DSBGA package.

* Optional Noise Reduction Capacitor.

Product

Folder

Sample &

Buy

Technical

Documents

Tools &

Software

Support &

Community

LP3985

SNVS087AE – OCTOBER 2000 – REVISED MAY 2015

LP3985 Micropower, 150-mA Low-Noise Ultra-Low-Dropout CMOS Voltage Regulator

1 Features

3 Description

The LP3985 is designed for portable and wireless

1

•

Input Voltage: 2.5 V to 6 V

applications with demanding performance and space

•

100-mV Maximum Dropout with 150-mA Load

requirements. LP3985 performance is optimized for

•

150-mA Verified Output

battery-powered systems to deliver ultra low noise,

extremely low dropout voltage, and low quiescent

•

current. Regulator ground current increases only

•

≤ 1.5-μA Quiescent Current when Shut Down

slightly in dropout, further prolonging the battery life.

•

Fast Turn-On time: 200

μs (typ.)

The LP3985 is stable with a small 1-µF ±30%

•

30-

ceramic or high-quality tantalum output capacitor. The

kHz

DSBGA requires the smallest possible PC board area

•

−40°C to 125°C Junction Temperature Range for

- the total application circuit area can be less than 2

Operation

mm x 2.5 mm, a fraction of a 1206 case size.

•

2.5-V, 2.6-V, 2.7-V, 2.8-V, 2.85-V, 2.9-V, 3-V, 3.1-

An optional external bypass capacitor reduces the

V, 3.2-V, 3.3-V, 4.7-V, 4.75-V, 4.8-V and 5-V

output noise without slowing down the load transient

Outputs Standard

response. Fast startup time is achieved by utilizing an

internal power-on circuit that actively pre-charges the

•

Logic Controlled Enable

bypass capacitor.

•

Stable with Ceramic and High-Quality Tantalum

Power supply rejection is better than 50 dB at low

Capacitors

frequencies and starts to roll off at 1 kHz. High power

•

Fast Turnon

supply rejection is maintained down to low input

•

Thermal Shutdown and Short-Circuit Current Limit

voltage levels common to battery operated circuits.

The device is ideal for mobile phone and similar

2 Applications

battery-powered wireless applications. It provides up

•

CDMA Cellular Handsets

to 150 mA, from a 2.5-V to 6-V input. The LP3985

consumes less than 1.5 µA in disable mode and has

•

Wideband CDMA Cellular Handsets

fast turn-on time less than 200 µs.

•

GSM Cellular Handsets

The LP3985 is available with fixed output voltages

•

Portable Information Appliances

from 2.5 V to 5 V. Contact Texas Instruments Sales

space

for specific voltage option needs.

Simplified Schematic

Device Information(1)

PART

PACKAGE

BODY SIZE

NUMBER

DSBGA (5)

1.502 mm x 1.045 mm (MAX)

LP3985

SOT-23 (5)

2.90 mm x 1.60 mm (NOM)

(1) For

all

available

packages,

see

the

Package

Option

Addendum at the end of the datasheet.

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.