DMOS

100mA Low-Dropout Regulator

FEATURES

q NEW DMOS TOPOLOGY:

Ultra Low Dropout Voltage:

60mV typ at 100mA

Output capacitor NOT required for stability

q FAST TRANSIENT RESPONSE

q VERY LOW NOISE: 23

q HIGH ACCURACY:

q HIGH EFFICIENCY:

q 2.5V, 2.8V, 2.85V, 3.0V, 3.3V, 5.0V, AND

ADJUSTABLE OUTPUT VERSIONS

q OTHER OUTPUT VOLTAGES AVAILABLE UPON

REQUEST

q FOLDBACK CURRENT LIMIT

q THERMAL PROTECTION

q SMALL SURFACE-MOUNT PACKAGES:

SOT23-5 and SO-8

APPLICATIONS

q PORTABLE COMMUNICATION DEVICES

q BATTERY-POWERED EQUIPMENT

q PERSONAL DIGITAL ASSISTANTS

q MODEMS

q BAR-CODE SCANNERS

q BACKUP POWER SUPPLIES

DESCRIPTION

The REG101 is a family of low-noise, low-dropout linear

regulators with low ground pin current. Its new DMOS

topology provides significant improvement over previous

designs, including low dropout voltage (only 60mV typ at

full load), and better transient performance. In addition, no

output capacitor is required for stability, unlike conventional

low-dropout regulators that are difficult to compensate and

require expensive low ESR capacitors greater than 1

µF.

Typical ground pin current is only 500

µA (at I

and drops to 10nA when not in enabled mode. Unlike regula-

tors with PNP pass devices, quiescent current remains rela-

tively constant over load variation and under dropout condi-

tions.

The REG101 has very low output noise (typically 23

µVrms

in portable communications equipment. Accuracy is main-

tained over temperature, line, and load variations. Key

parameters are tested over the specified temperature range

(–40

°C to +85°C).

The REG101 is well protected—internal circuitry provides a

current limit that protects the load from damage. Thermal

protection circuitry keeps the chip from being damaged by

excessive temperature. The REG101 is available in the

SOT23-5 and the SO-8 packages.

REG101

(Fixed Voltage

Versions)

Enable

Gnd

0.1

µF

C

OUT

(1)

+

+

V

OUT

V

IN

NR

NR = Noise Reduction

NOTE: (1) Optional.

REG101-A

Gnd

Enable

0.1

µF

+

C

OUT

(1)

+

V

OUT

V

IN

R

2

R

1

Adj

REG1

01

REG101

SBVS026C – JULY 2001

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 2000, Texas Instruments Incorporated

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.