FEATURES

NEW DMOS TOPOLOGY:

Ultra Low Dropout Voltage:

60mV typ at 100mA

Output capacitor NOT required for stability

FAST TRANSIENT RESPONSE

VERY LOW NOISE: 23μVrms

HIGH ACCURACY: ±1.5% max

HIGH EFFICIENCY:

IGND = 500μA at IOUT = 100mA

Not Enabled: IGND = 10nA

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

ADJUSTABLE OUTPUT VERSIONS

OTHER OUTPUT VOLTAGES AVAILABLE

UPON REQUEST

FOLDBACK CURRENT LIMIT

THERMAL PROTECTION

SMALL SURFACE-MOUNT PACKAGES:

SOT23-5 and SO-8

APPLICATIONS

PORTABLE COMMUNICATION DEVICES

BATTERY-POWERED EQUIPMENT

PERSONAL DIGITAL ASSISTANTS

MODEMS

BAR-CODE SCANNERS

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 1μF.

Typical ground pin current is only 500μA (at IOUT = 100mA)

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

with PNP pass devices, quiescent current remains relatively

constant over load variation and under dropout conditions.

The REG101 has very low output noise (typically 23μVrms

for VOUT = 3.3V with CNR = 0.01μF), making it ideal for use

in portable communications equipment. Accuracy is maintained

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.