DMOS

1A Low-Dropout Regulator

FEATURES

q NEW DMOS TOPOLOGY:

Ultra Low Dropout Voltage:

230mV typ at 1A and 3.3V Output

Output Capacitor NOT Required for Stability

q FAST TRANSIENT RESPONSE

q VERY LOW NOISE: 33

RMS

q HIGH ACCURACY:

q HIGH EFFICIENCY:

q 2.5V, 2.7V, 3.0V, 3.3V, 5.0V AND

ADJUSTABLE OUTPUT VERSIONS

q THERMAL PROTECTION

q SMALL SURFACE-MOUNT PACKAGES:

SOT223-5, DDPAK-5

APPLICATIONS

q PORTABLE COMMUNICATION DEVICES

q BATTERY-POWERED EQUIPMENT

q MODEMS

q BAR-CODE SCANNERS

q BACKUP POWER SUPPLIES

DESCRIPTION

The REG104 is a family of low-noise, low-dropout linear

regulators with low ground pin current. Its new DMOS topol-

ogy provides significant improvement over previous designs,

including low dropout voltage (only 230mV 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.

drops to 0.5

µA in not enabled mode. Unlike regulators with

PNP pass devices, quiescent current remains relatively con-

stant over load variations and under dropout conditions.

The REG104 has very low output noise (typically 33

µV

RMS

in portable communications equipment. On-chip trimming

results in high output voltage accuracy. Accuracy is main-

tained over temperature, line, and load variations. Key pa-

rameters are tested over the specified temperature range

(–40

°C to +85°C).

The REG104 is well protected—internal circuitry provides a

current limit which protects the load from damage. Thermal

protection circuitry keeps the chip from being damaged by

excessive temperature. The REG104 is available in the

DDPAK-5 and the SOT223-5.

REG

104

REG104

REG104

(Fixed Voltage

Versions)

Enable

Gnd

0.1

µF

C

OUT

(1)

+

+

V

OUT

V

IN

NR

NR = Noise Reduction

NOTE: (1) Optional.

REG104-A

Gnd

Enable

0.1

µF

+

C

OUT

(1)

+

V

OUT

V

IN

R

2

R

1

Adj

REG104

SBVS025G – SEPTEMBER 2001 – REVISED SEPTEMBER 2005

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 © 2001-2005, 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.

All trademarks are the property of their respective owners.