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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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
ADP3309
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 1998
anyCAP 100 mA
Low Dropout Linear Regulator
FUNCTIONAL BLOCK DIAGRAM
THERMAL
PROTECTION
DRIVER
G
M
CC
IN
ADP3309
OUT
R1
R2
GND
Q1
ERR/
NC
SD
BANDGAP
REF
Q2
FEATURES
6
1.2% Accuracy Over Line and Load Regulations @ +25
8
C
Ultralow Dropout Voltage: 120 mV Typical @ 100 mA
Requires Only C
O
= 0.47
m
F for Stability
anyCAP = Stable with All Types of Capacitors
(Including MLCC)
Current and Thermal Limiting
Low Noise
Low Shutdown Current: 1
m
A
3.0 V to 12 V Supply Range
–20
8
C to +85
8
C Ambient Temperature Range
Several Fixed Voltage Options
Ultrasmall SOT-23-5 Package
Excellent Line and Load Regulations
APPLICATIONS
Cellular Telephones
Notebook, Palmtop Computers
Battery Powered Systems
PCMCIA Regulator
Bar Code Scanners
Camcorders, Cameras
GENERAL DESCRIPTION
The ADP3309 is a member of the ADP330x family of precision
low dropout anyCAP voltage regulators. It is pin-for-pin and
functionally compatible with National’s LP2981, but offers
performance advantages. The ADP3309 stands out from con-
ventional LDOs with a novel architecture and an enhanced
process. Its patented design requires only a 0.47
μ
F output
capacitor for stability. This device is stable with any type of
capacitor regardless of its ESR (Equivalent Series Resistance)
value, including ceramic types for space restricted applications.
The ADP3309 achieves
±
1.2% accuracy at room temperature
and
±
2.2% overall accuracy over temperature, line and load
regulations. The dropout voltage of the ADP3309 is only
120 mV (typical) at 100 mA. This device also includes a current
limit and a shutdown feature. In shutdown mode, the ground
current is reduced to ~1
μ
A.
The ADP3309 operates with a wide input voltage range from
3.0 V to 12 V and delivers a load current in excess of 100 mA.
The ADP3309 anyCAP LDO offers a wide range of output
voltages. For a 50 mA version, refer to the ADP3308 data sheet.
V
OUT
= +3.3V
V
IN
+
–
ADP3309-3.3
IN
OUT
ERR/
NC
ON
OFF
SD
GND
C2
0.47
m
F
C1
0.47
m
F
+
–
Figure 1. Typical Application Circuit
anyCAP is a trademark of Analog Devices, Inc.