REV. 0

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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

CC

IN

ADP3309

OUT

R1

R2

GND

Q1

ERR/NC

SD

BANDGAP

REF

Q2

FEATURES

1.2% Accuracy Over Line and Load Regulations @ +25 C

Ultralow Dropout Voltage: 120 mV Typical @ 100 mA

F for Stability

anyCAP = Stable with All Types of Capacitors

(Including MLCC)

Current and Thermal Limiting

Low Noise

Low Shutdown Current: 1

A

3.0 V to 12 V Supply Range

–20 C to +85 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

µF 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

µA.

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.

+

–

ADP3309-3.3

OUT

ERR/NC

ON

OFF

SD

GND

IN

C2

0.47 F

C1

0.47 F

+

–

Figure 1. Typical Application Circuit

anyCAP is a trademark of Analog Devices, Inc.