REV. 0

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a

ADP1109

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

Micropower Low Cost

Fixed 3.3 V, 5 V, 12 V and Adjustable

DC-to-DC Converter

FUNCTIONAL BLOCK DIAGRAMS

DRIVER

SW

GND

COMPARATOR

A1

R1

SENSE

R2

250k

SHUTDOWN

+

ADP1109-3.3: R1 = 152k

ADP1109-5:

R1 = 83k

ADP1109-12: R1 = 29k

Q1

120kHz

OSCILLATOR

1.25V

REFERENCE

Fixed Output

DRIVER

SW

GND

COMPARATOR

A1

FB

SHUTDOWN

+

ADP1109

Q1

120kHz

OSCILLATOR

1.25V

REFERENCE

Adjustable Output

FEATURES

Operates at Supply Voltages 2 V to 12 V

Fixed 3.3 V, 5 V, 12 V and Adjustable Output

Minimum External Components Required

Ground Current: 320

A

Oscillator Frequency: 120 kHz

Logic Shutdown

8-Lead DIP and SO-8 Packages

APPLICATIONS

Cellular Telephones

Single-Cell to 5 V Converters

Laptop and Palmtop Computers

Pagers

Cameras

Battery Backup Supplies

Portable Instruments

Laser Diode Drivers

Hand-Held Inventory Computers

GENERAL DESCRIPTION

The ADP1109 is a versatile step-up switching regulator. The

device requires only minimal external components to operate as

a complete switching regulator.

The ADP1109-5 can deliver 100 mA at 5 V from a 3 V input

and the ADP1109-12 can deliver 60 mA at 12 V from a 5 V

input. The device also features a logic controlled shutdown

capability that, when a logic low is applied, will shut down the

oscillator.

The 120 kHz operating frequency allows for the use of small

surface mount components. The gated oscillator capability

eliminates the need for frequency compensation.

TYPICAL APPLICATION

SW

GND

ADP1109-12

+

D1

C1

22 F

16V

SENSE

L1

33 H

5V

SHUTDOWN

SHUTDOWN/PROGRAM

12V

60mA

Flash Memory VPP Generator