R
E
G
1
0
3
REG103
REG103
R
E
G
1
0
3
SBVS010D – JANUARY 2000 – REVISED SEPTEMBER 2005
DMOS
500mA Low-Dropout Regulator
DESCRIPTION
FEATURES
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.
● NEW DMOS TOPOLOGY:
Ultra Low Dropout Voltage:
115mV Typ at 500mA and 3.3V Output
Output Capacitor NOT Required for Stability
● FAST TRANSIENT RESPONSE
●
VERY LOW NOISE: 33µVrms
● HIGH ACCURACY: ±2% max
● HIGH EFFICIENCY:
IGND = 1mA at IOUT = 500mA
Not Enabled: IGND = 0.5µA
● 2.5V, 2.7V, 3.0V, 3.3V, 5.0V, AND ADJUSTABLE
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.
OUTPUT VERSIONS
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 main-
tained over temperature, line, and load variations. Key
parameters are tested over the specified temperature range
(–40°C to +85°C).
● FOLDBACK CURRENT LIMIT
● THERMAL PROTECTION
● OUTPUT VOLTAGE ERROR INDICATOR(1)
● SMALL SURFACE-MOUNT PACKAGES:
SOT223-5, DDPAK-5, SO-8
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 protected—internal cir-
cuitry 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.
APPLICATIONS
● PORTABLE COMMUNICATION DEVICES
● BATTERY-POWERED EQUIPMENT
● PERSONAL DIGITAL ASSISTANTS
● MODEMS
● BAR-CODE SCANNERS
● BACKUP POWER SUPPLIES
ENABLE ERROR(1)
ERROR1)
ENABLE
VOUT
VIN
VOUT
VIN
REG103
(Fixed Voltage
Versions)
+
R1
Adj
R2
+
+
+
0.1µF
(2)
(2)
COUT
REG103-A
COUT
0.1µF
NR
Gnd
Gnd
NR = Noise Reduction
NOTE: (1) SO-8 Package Only. (2) Optional.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright © 2000-2005, Texas Instruments Incorporated
www.ti.com
TI [ TEXAS INSTRUMENTS ]
