REV. 0

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a

ADP3000

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

World Wide Web Site: http://www.analog.com

Fax: 617/326-8703

© Analog Devices, Inc., 1997

Micropower Step-Up/Step-Down

Fixed 3.3 V, 5 V, 12 V and Adjustable

High Frequency Switching Regulator

FUNCTIONAL BLOCK DIAGRAM

COMPARATOR

GAIN BLOCK/

ERROR AMP

400kHz

OSCILLATOR

DRIVER

A1

1.245V

REFERENCE

R1

R2

ADP3000

SET

GND

SENSE

A0

SW1

SW2

FEATURES

Operates at Supply Voltages from 2 V to 30 V

Works in Step-Up or Step-Down Mode

Very Few External Components Required

High Frequency Operation Up to 400 kHz

Low Battery Detector on Chip

User Adjustable Current Limit

Fixed and Adjustable Output Voltage

8-Pin DIP and SO-8 Package

Small Inductors and Capacitors

APPLICATIONS

Notebook, Palmtop Computers

Cellular Telephones

Hard Disk Drives

Portable Instruments

Pagers

GENERAL DESCRIPTION

The ADP3000 is a versatile step-up/step-down switching

regulator that operates from an input supply voltage of 2 V to

12 V in step-up mode and up to 30 V in step-down mode.

The ADP3000 operates in Pulse Frequency Mode (PFM) and

consumes only 500

µA, making it highly suitable for applica-

tions that require low quiescent current.

The ADP3000 can deliver an output current of 100 mA at

3 V from a 5 V input in step-down configuration and 180 mA at

3.3 V from a 2 V input in step-up configuration.

The auxiliary gain amplifier can be used as a low battery detector,

linear regulator undervoltage lockout or error amplifier.

The ADP3000 operates at 400 kHz switching frequency. This

allows the use of small external components (inductors and

capacitors), making the device very suitable for space constrained

designs.

ADP3000-3.3V

1

2

3

8

4

5

SW1

FB

(SENSE)

SW2

GND

+

100µF

10V

120

Ω

6.8µH

IN5817

C1

100µF

10V

2V–3.2V

3.3V @

180mA

C1, C2: AVX TPS D107 M010R0100

L1: SUMIDA CD43-6R8

Figure 1. Typical Application

ADP3000

1

2

3

8

4

5

FB

SW2

GND

C1

100µF

10V

120

Ω

L1

10µH

5V–6V

C1, C2: AVX TPS D107 M010R0100

L1: SUMIDA CD43-100

+

D1

1N5818

CL

100µF

10V

R2

150k

Ω

1%

R1

110k

Ω

1%

3V

100mA

Figure 2. Step-Down Mode Operation