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.