REV. A

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a

ADP3605

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., 1999

120 mA Switched Capacitor

Voltage Inverter with Regulated Output

FUNCTIONAL BLOCK DIAGRAM

SD

OSC

CLOCK

GEN

FEEDBACK

CONTROL

LOOP

SD

SD

B

S

D

S

D

N

C

C

PN

N

S1

S3

GND

S2

S4

ADP3605

+

–3.0V

4.7 F

+

4.7 F

+

ADP3605-3

4.7 F

OFF

ON

0

SD

*FOR BEST PERFORMANCE, 10 F IS RECOMMENDED

GND

Figure 1. Typical Application Circuit

FEATURES

Fully Regulated Output Voltage (–3 V and Adjustable)

High Output Current: 120 mA

Output Accuracy:

3%

250 kHz Switching Frequency

Low Shutdown Current: 2

A Typical

Input Voltage Range from 3 V to 6 V

SO-8 and RU-14 Packages

–40 C to +85 C Ambient Temperature Range

APPLICATIONS

Voltage Inverters

Voltage Regulators

Computer Peripherals and Add-On Cards

Portable Instruments

Battery Powered Devices

Pagers and Radio Control Receivers

Disk Drives

Mobile Phones

GENERAL DESCRIPTION

The ADP3605 is a 120 mA regulated output switched capacitor

voltage inverter. It provides a regulated output voltage with

minimum voltage loss and requires a minimum number of ex-

ternal components. In addition, the ADP3605 does not require

the use of an inductor.

Pin-for-pin and functionally compatible with the ADP3604, the

internal oscillator of the ADP3605 runs at 500 kHz nominal

frequency which produces an output switching frequency of

250 kHz. This allows for the use of smaller charge pump and

filter capacitors.

The ADP3605 provides an accuracy of

±3% with a typical shut-

down current of 2

µA. It can also operate from a single positive

input voltage as low as 3 V. The ADP3605 is offered with the

regulation fixed at –3 V or adjustable via external resistors over

a –3 V to –6 V range.