FEATURES
NEW DMOS TOPOLOGY:
Ultra Low Dropout Voltage:
230mV typ at 1A and 3.3V Output
Output Capacitor NOT Required for Stability
FAST TRANSIENT RESPONSE
VERY LOW NOISE: 33μVRMS
HIGH ACCURACY: ±2% max
HIGH EFFICIENCY:
IGND = 1.7mA at IOUT = 1A
Not Enabled: IGND = 0.5μA
2.5V, 2.7V, 3.0V, 3.3V, 5.0V AND
ADJUSTABLE OUTPUT VERSIONS
THERMAL PROTECTION
SMALL SURFACE-MOUNT PACKAGES:
SOT223-5, DDPAK-5

APPLICATIONS
PORTABLE COMMUNICATION DEVICES
BATTERY-POWERED EQUIPMENT
MODEMS
BAR-CODE SCANNERS
BACKUP POWER SUPPLIES

DESCRIPTION
The REG104 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 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 1μF.
Typical ground pin current is only 1.7mA (at IOUT = 1A) and
drops to 0.5μA in not enabled mode. Unlike regulators with
PNP pass devices, quiescent current remains relatively constant
over load variations and under dropout conditions.
The REG104 has very low output noise (typically 33μVRMS
for VOUT = 3.3V with CNR = 0.01μF), making it ideal for use
in portable communications equipment. On-chip trimming
results in high output voltage accuracy. Accuracy is maintained
over temperature, line, and load variations. Key parameters
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.