REG104
REG
104
REG
104
SBVS025G – SEPTEMBER 2001 – REVISED SEPTEMBER 2005
DMOS
1A Low-Dropout Regulator
FEATURES
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NEW DMOS TOPOLOGY:
Ultra Low Dropout Voltage:
230mV typ at 1A and 3.3V Output
Output Capacitor NOT Required for Stability
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FAST TRANSIENT RESPONSE
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VERY LOW NOISE: 33
µ
V
RMS
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HIGH ACCURACY:
±
2% max
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HIGH EFFICIENCY:
I
GND
= 1.7mA at I
OUT
= 1A
Not Enabled: I
GND
= 0.5
µ
A
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2.5V, 2.7V, 3.0V, 3.3V, 5.0V AND
ADJUSTABLE OUTPUT VERSIONS
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THERMAL PROTECTION
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SMALL SURFACE-MOUNT PACKAGES:
SOT223-5, DDPAK-5
DESCRIPTION
The REG104 is a family of low-noise, low-dropout linear
regulators with low ground pin current. Its new DMOS topol-
ogy 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 I
OUT
= 1A) and
drops to 0.5µA in
not enabled
mode. Unlike regulators with
PNP pass devices, quiescent current remains relatively con-
stant over load variations and under dropout conditions.
The REG104 has very low output noise (typically 33µV
RMS
for V
OUT
= 3.3V with C
NR
= 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 pa-
rameters 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.
APPLICATIONS
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PORTABLE COMMUNICATION DEVICES
BATTERY-POWERED EQUIPMENT
MODEMS
BAR-CODE SCANNERS
BACKUP POWER SUPPLIES
Enable
V
IN
+
0.1µF
REG104
(Fixed Voltage
Versions)
Gnd
+
V
OUT
C
OUT(1)
V
IN
+
0.1µF
Enable
V
OUT
REG104-A
R
1
Adj
Gnd
R
2
+
C
OUT(1)
NR
NR = Noise Reduction
NOTE: (1) 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 © 2001-2005, Texas Instruments Incorporated
www.ti.com
TI [ TEXAS INSTRUMENTS ]
