OUT

S/D

0.1 PF

10 PF

Ceramic

OUT

S/D

GND

IN

BIAS

LP38841

IN

BIAS

5V

± 10%

GND

GND

4.7 PF

*

LP38841

www.ti.com

SNVS289B – DECEMBER 2004 – REVISED SEPTEMBER 2006

LP38841 0.8A Ultra Low Dropout Linear Regulators

Stable with Ceramic Output Capacitors

Check for Samples: LP38841

1

FEATURES

•

Available in 5 lead TO220 and TO263 packages

•

−40°C to +125°C junction temperature range

2

•

Ideal for conversion from 1.8V or 1.5V inputs

•

Designed for use with low ESR ceramic

APPLICATIONS

capacitors

•

ASIC Power Supplies In:

•

0.8V, 1.2V and 1.5V standard voltages

available

–

- Desktops, Notebooks, and Graphics

Cards, Servers

•

Ultra low dropout voltage (75mV @ 0.8A typ)

–

- Gaming Set Top Boxes, Printers and

•

1.5% initial output accuracy

Copiers

•

Load regulation of 0.1%/A (typical)

•

Server Core and I/O Supplies

•

30nA quiescent current in shutdown (typical)

•

DSP and FPGA Power Supplies

•

Low ground pin current at all loads

•

SMPS Post-Regulator

•

Over temperature/over current protection

DESCRIPTION

The LP38841 is a high current, fast response regulator which can maintain output voltage regulation with

minimum input to output voltage drop. Fabricated on a CMOS process, the device operates from two input

voltages: Vbias provides voltage to drive the gate of the N-MOS power transistor, while Vin is the input voltage

which supplies power to the load. The use of an external bias rail allows the part to operate from ultra low Vin

voltages. Unlike bipolar regulators, the CMOS architecture consumes extremely low quiescent current at any

output load current. The use of an N-MOS power transistor results in wide bandwidth, yet minimum external

capacitance is required to maintain loop stability.

The fast transient response of these devices makes them suitable for use in powering DSP, Microcontroller Core

voltages and Switch Mode Power Supply post regulators. The parts are available in TO-220 and TO-263

packages.

Dropout Voltage: 75 mV (typ) @ 0.8A load current.

Quiescent Current: 30 mA (typ) at full load.

Shutdown Current: 30 nA (typ) when S/D pin is low.

Precision Output Voltage: 1.5% room temperature accuracy.

Typical Application Circuit

* Minimum value required if Tantalum capacitor is used (see Application Hints).

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2006, 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.