The REG103 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 115mV 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 1mA (at IOUT = 500mA)
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 REG103 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 SO-8 version of the REG103 has an ERROR\ pin that
provides a power good flag, indicating the regulator is in
regulation. The REG103 is well protectedinternal circuitry
provides a current limit that protects the load from
damage. Thermal protection circuitry keeps the chip from
being damaged by excessive temperature. In addition to the
SO-8 package, the REG103 is also available in the DDPAK
and the SOT223-5.