LP3891

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SNVS235D – SEPTEMBER 2003 – REVISED APRIL 2013

LP3891 0.8A Fast-Response Ultra Low Dropout Linear Regulators

Check for Samples: LP3891

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FEATURES

DESCRIPTION

The LP3891 is a high current, fast response regulator

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•

Ultra Low Dropout Voltage (100mV at 0.8A typ)

which can maintain output voltage regulation with

•

Low Ground Pin Current

minimum input to output voltage drop. Fabricated on

•

Load Regulation of 0.04%/A

a CMOS process, the device operates from two input

voltages: Vbias provides voltage to drive the gate of

•

60 nA Typical Quiescent Current in Shutdown

the N-MOS power transistor, while Vin is the input

•

1.5% Output Accuracy (25°C)

voltage which supplies power to the load. The use of

•

TO-220, DDPAK/TO-263 and SO PowerPAD-8

an external bias rail allows the part to operate from

Packages

ultra low Vin voltages. Unlike bipolar regulators, the

CMOS

architecture

consumes

extremely

low

•

Over Temperature/Over Current Protection

quiescent current at any output load current. The use

•

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

of an N-MOS power transistor results in wide

bandwidth, yet minimum external capacitance is

APPLICATIONS

required to maintain loop stability.

•

DSP Power Supplies

The fast transient response of these devices makes

•

Server Core and I/O Supplies

them

suitable

for

use

in

powering

DSP,

Microcontroller Core voltages and Switch Mode

•

PC Add-in-Cards

Power Supply post regulators. The parts are available

•

Local Regulators in Set-Top Boxes

in TO-220, DDPAK/TO-263 and SO PowerPAD-8

•

Microcontroller Power Supplies

packages.

•

High Efficiency Power Supplies

Dropout Voltage: 100 mV (typ) at 0.8A load current.

•

SMPS Post-Regulators

Ground Pin Current: 3 mA (typ) at full load.

Shutdown Current: 60 nA (typ) when S/D pin is low.

Precision Output Voltage: 1.5% room temperature

accuracy.

TYPICAL APPLICATION CIRCUIT

At least 10 µF of input and output capacitance is required for stability.

*Tantalum capacitors are recommended. Aluminum electrolytic capacitors may be used for restricted temperature

range. See application hints.

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PRODUCTION DATA information is current as of publication date.

Copyright © 2003–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.