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.