Data Sheet
FEATURES
5.5 V Input, 500 mA, Low Quiescent
Current, CMOS Linear Regulators
TYPICAL APPLICATION CIRCUITS
V
OUT
= 3.3V
C2
1
4
GND
EN
5
OFF
APPLICATIONS
Digital camera and audio devices
Portable and battery-powered equipment
Automatic meter reading (AMR) meters
GPS and location management units
Medical instrumentation
Point of load power
Figure 2. ADP 125 with Adjustable Output Voltage
GENERAL DESCRIPTION
The ADP124/ADP125 are low quiescent current, low dropout
linear regulators. They are designed to operate from an input
voltage between 2.3 V and 5.5 V and to provide up to 500 mA
of output current. The low 130 mV dropout voltage at a 500 mA
load improves efficiency and allows operation over a wide input
voltage range.
The low 210 μA of quiescent current with a 500 mA load makes the
ADP124/ADP125 ideal for battery-operated portable equipment.
The ADP124 is capable of 31 fixed-output voltages from 1.75 V
to 3.3 V. The ADP125 is the adjustable version of the device and
allows the output voltage to be set between 0.8 V and 5.0 V by
an external voltage divider.
The ADP124/ADP125 are specifically designed for stable operation
with tiny 1 µF ceramic input and output capacitors to meet the
requirements of high performance, space constrained applications.
The ADP124/ADP125 have an internal soft start that gives a
constant start-up time of 350 µs. Short-circuit protection and
thermal overload protection circuits prevent damage in adverse
conditions. The ADP124/ADP125 are available in 8-lead
exposed paddle MSOP and LFCSP packages. When compared
with the standard MSOP and LFCSP packages, the exposed
paddle MSOP and LFCSP packages have lower thermal resistance
(θ
JA
). The lower thermal resistance package allows the ADP124/
ADP125 to meet the needs of a variety of portable applications
while minimizing the rise in junction temperature.
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
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One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113 ©2009–2012 Analog Devices, Inc. All rights reserved.
08476-002
Input voltage supply range: 2.3 V to 5.5 V
500 mA maximum output current
Fixed and adjustable output voltage versions
1% initial accuracy
Up to 31 fixed-output voltage options available
from 1.75 V to 3.3 V
Adjustable-output voltage range from 0.8 V to 5.0 V
Very low dropout voltage: 130 mV
Low quiescent current: 45 µA
Low shutdown current: <1 µA
Excellent PSRR performance: 60 dB at 100 kHz
Excellent load/line transient response
Optimized for small 1.0 μF ceramic capacitors
Current limit and thermal overload protection
Logic controlled enable
Compact 8-lead exposed paddle MSOP and LFCSP packages
VOUT
VOUT
VOUT
SENSE
GND
VIN
VIN
NC
EN
8
ADP124
2
7
V
IN
= 5.5V
C1
3
6
4
5
OFF
Figure 1. ADP124 with Fixed Output Voltage
V
OUT
= 3.3V
1
VOUT
VOUT
ADJ
VIN
VIN
NC
8
V
IN
= 5.5V
C1
ADP125
C2
R1
2
7
3
6
R2
ON
08476-001
ON
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