600 mA/1000 mA, 2.5 MHz Buck-Boost

DC-to-DC Converters

Data Sheet

ADP2503/ADP2504

Rev. D

Document Feedback

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibilityis assumedbyAnalogDevicesforitsuse,norforanyinfringementsof patentsorother

rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

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

Tel: 781.329.4700

©2008–2015 Analog Devices, Inc. All rights reserved.

Technical Support

www.analog.com

FEATURES

1 mm height profile

Compact PCB footprint

Seamless transition between modes

38 μA typical quiescent current

2.5 MHz operation enables 1.5 μH inductor

Input voltage: 2.3 V to 5.5 V

Fixed output voltage: 2.8 V to 5.0 V

Adjustable model output voltage range: 2.8 V to 5.5 V

600 mA (ADP2503) and 1000 mA (ADP2504) output options

Boost converter configuration with load disconnect

SYNC pin with three different modes

Power save mode (PSM) for improved light load efficiency

Forced fixed frequency operation mode

Synchronization with external clock

Internal compensation

Soft start

Enable/shutdown logic input

Overtemperature protection

Short-circuit protection

Undervoltage lockout protection

Small 10-lead 3 mm × 3 mm LFCSP (QFN) package

Supported by ADIsimPower™ design tool

APPLICATIONS

Wireless handsets

Digital cameras/portable audio players

Miniature hard disk power supplies

USB powered devices

GENERAL DESCRIPTION

The ADP2503/ADP2504 are high efficiency, low quiescent current

step-up/step-down dc-to-dc converters that can operate at input

voltages greater than, less than, or equal to the regulated output

voltage. The power switches and synchronous rectifiers are

internal to minimize external device count. At high load currents,

the ADP2503/ADP2504 use a current-mode, fixed frequency

pulse-width modulation (PWM) control scheme for optimal

stability and transient response. To ensure the longest battery life

in portable applications, the ADP2503/ADP2504 have an optional

power save mode that reduces the switching frequency under

light load conditions. For wireless and other low noise applica-

tions where variable frequency power save mode may cause

interference, the logic control input sync forces fixed frequency

PWM operation under all load conditions.

The ADP2503/ADP2504 can run from input voltages between

2.3 V and 5.5 V, allowing single lithium or lithium polymer cell,

multiple alkaline or NiMH cells, PCMCIA, USB, and other stan-

dard power sources. The ADP2503/ADP2504 have fixed output

options, or using the adjustable model, the output voltage can

be programmed through an external resistor divider. Compensa-

tion is internal to minimize the number of external components.

During logic-controlled shutdown, the input is disconnected

from the output and draws less than 1 μA from the input source.

Operating as boost converters, the ADP2503/ADP2504 feature a

true load disconnect function that isolates the load from the

power source. Other key features include undervoltage lockout

to prevent deep battery discharge, and soft start to prevent input

current overshoot at startup.

TYPICAL APPLICATION CIRCUIT

SW1

1.5µH

PVIN

2.3V TO 5.5V

2.8V TO 5V

22µF

10µF

ADP2503/ADP2504

VIN

VOUT

SW2

FB

THREE DIFFERENT MODES.

EN

OFF

ON

PGND

AGND

Figure 1.