ANALOG DEVICES ADP2504 Service Manual

600 mA/1000 mA, 2.5 MHz Buck-Boost

2.3V

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FEATURES FEATURES

1 mm height profile 1 mm height profile
Compact PCB footprint Compact PCB footprint
Seamless transition between modes Seamless transition between modes
38 A typical quiescent current 38 A typical quiescent current

2.5 MHz operation enables 1 µH inductor 2.5 MHz operation enables 1 µH inductor
Input voltage: 2.3 V to 5.5 V Input voltage: 2.3 V to 5.5 V
Fixed output voltage: 2.8 V to 5.0 V Fixed output voltage: 2.8 V to 5.0 V
600 mA (ADP2503) and 1000 mA (ADP2504) output options 600 mA (ADP2503) and 1000 mA (ADP2504) output options
Boost converter configuration with load disconnect Boost converter configuration with load disconnect
SYNC pin with three different modes: SYNC pin with three different modes:

Power save mode (PSM) for improved light load efficiency Power save mode (PSM) for improved light load efficiency
Forced fixed frequency operation mode Forced fixed frequency operation mode

Synchronization with external clock Synchronization with external clock
Internal compensation Internal compensation
Soft start Soft start
Enable/shutdown logic input Enable/shutdown logic input
Overtemperature protection Overtemperature protection
Short-circuit protection Short-circuit protection
Undervoltage lockout protection Undervoltage lockout protection
Small 10-lead 3 mm × 3 mm LFCSP/QFN package Small 10-lead 3 mm × 3 mm LFCSP/QFN package

APPLICATIONS APPLICATIONS

Wireless handsets Wireless handsets
Digital cameras/portable audio players Digital cameras/portable audio players
Miniature hard disk power supplies Miniature hard disk power supplies
USB powered devices USB powered devices

DC-to-DC Converters

ADP2503/ADP2504

GENERAL DESCRIPTION GENERAL DESCRIPTION

The ADP2503/ADP2504 are high efficiency, low quiescent current

The ADP2503/ADP2504 are high efficiency, low quiescent current
step-up/step-down dc-to-dc converters that can operate at input

step-up/step-down dc-to-dc converters that can operate at input
voltages greater than, less than, or equal to the regulated output

voltages greater than, less than, or equal to the regulated output
voltage. The power switches and synchronous rectifiers are

voltage. The power switches and synchronous rectifiers are
internal to minimize external part count. At high load currents,

internal to minimize external part count. At high load currents,
the ADP2503/ADP2504 use a current-mode, fixed frequency

the ADP2503/ADP2504 use a current-mode, fixed frequency
pulse-width modulation (PWM) control scheme for optimal

pulse-width modulation (PWM) control scheme for optimal
stability and transient response. To ensure the longest battery life

stability and transient response. To ensure the longest battery life
in portable applications, the ADP2503/ADP2504 have an

in portable applications, the ADP2503/ADP2504 have an
optional power save mode that reduces the switching frequency

optional power save mode that reduces the switching frequency
under light load conditions. For wireless and other low noise

under light load conditions. For wireless and other low noise
applications where variable frequency power save mode may

applications where variable frequency power save mode may
cause interference, the logic control input sync forces fixed

cause interference, the logic control input sync forces fixed
frequency PWM operation under all load conditions.

frequency PWM operation under all load conditions.

The ADP2503/ADP2504 can run from input voltages between

The ADP2503/ADP2504 can run from input voltages between

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

2.3 V and 5.5 V, allowing single lithium or lithium polymer cell,
multiple alkaline or NiMH cells, PCMCIA, USB, and other

multiple alkaline or NiMH cells, PCMCIA, USB, and other
standard power sources. The ADP2503/ADP2504 have fixed

standard power sources. The ADP2503/ADP2504 have fixed
output options ranging from 2.8 V to 5 V. Compensation is

output options ranging from 2.8 V to 5 V. Compensation is
internal to minimize the number of external components.

internal to minimize the number of external components.

During logic-controlled shutdown, the input is disconnected

During logic-controlled shutdown, the input is disconnected
from the output and draws less than 1 µA from the input source.

from the output and draws less than 1 µA from the input source.
Operating as boost converters, the ADP2503/ADP2504 feature

Operating as boost converters, the ADP2503/ADP2504 feature
a true load disconnect function that isolates the load from the

a true load disconnect function that isolates the load from the
power source. Other key features include undervoltage lockout

power source. Other key features include undervoltage lockout
to prevent deep battery discharge and soft start to prevent input

to prevent deep battery discharge and soft start to prevent input
current overshoot at startup.

current overshoot at startup.

TYPICAL APPLICATION CIRCUIT TYPICAL APPLICATION CIRCUIT

SW1

V

IN

TO 5.5V

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.

ADP2503

PVIN

VIN

SYNC

EN

ON

OFF

1.0µH

SW2

V

OUT

VOUT

FB

AGND

PGND

Figure 1.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2008 Analog Devices, Inc. All rights reserved.

2.8V TO 5V

22µF10µF

07475-001

ADP2503/ADP2504

www.BDTIC.com/ADI

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1

General Description ......................................................................... 1

Typical Application Circuit ............................................................. 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Absolute Maximum Ratings ............................................................ 4

Thermal Resistance ...................................................................... 4

ESD Caution .................................................................................. 4

Pin Configuration and Function Descriptions ............................. 5

Typical Performance Characteristics ............................................. 6

Theory of Operation ...................................................................... 11

Power Save Mode ........................................................................ 11

REVISION HISTORY

10/08—Revision 0: Initial Version

Soft Start ...................................................................................... 11

Sync Function ............................................................................. 11

Enable ........................................................................................... 11

Undervoltage Lockout ............................................................... 12

Thermal Shutdown .................................................................... 12

Short-Circuit Protection ............................................................ 12

Reverse Current Limit ............................................................... 12

Applications Information .............................................................. 13

Inductor Selection ...................................................................... 13

PCB Layout Guidelines .................................................................. 15

Outline Dimensions ....................................................................... 16

Ordering Guide .......................................................................... 16

Rev. 0 | Page 2 of 16

ADP2503/ADP2504

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SPECIFICATIONS

VIN = 3.6 V, V
unless otherwise noted.

Table 1.

Parameters Conditions Min Typ Max Unit

INPUT CHARACTERISTICS

Input Voltage Range 2.3 5.5 V

Undervoltage Lockout Threshold VIN rising 2.15 2.20 2.25 V

Undervoltage Lockout Threshold VIN falling 2.10 2.14 2.20 V

OUTPUT CHARACTERISTICS

Output Voltage Range 2.8 5.0 V

Feedback Impedance 450 kΩ

Output Voltage Initial Accuracy ADP2503/ADP2504 (PWM operation, no load) −2 +2 %

Load and Line Regulation VIN = 2.3 V to 3.6 V, I

V

CURRENT CHARACTERISTICS

Quiescent Current (VIN) I

Shutdown Current TA = TJ = −40°C to +85°C 0.2 1 µA

SWITCH CHARACTERISTICS

N-Channel Switches (LFCSP) VIN = 3.6 V 150 mΩ

P-Channel Switches (LFCSP) VIN = V

P-Channel Leakage TJ = −40°C to +85°C 1 µA

Switch Current Limit

ADP2504 1.3 2.0 A
ADP2503 1.0 1.4 A

Reverse Current Limit 1.1 A

OSCILLATOR AND STARTUP

Oscillator Frequency 2.1 2.5 2.9 MHz
On Time PMOS1 (Buck Mode) Minimum duty cycle = 30% 130 ns
On Time NMOS2 (Boost Mode) Maximum duty cycle = 50% (×2) 200 ns
Sync Clock Frequency 2.2 2.8 MHz
Sync Clock Minimum Off Time 160 ns

LOGIC LEVEL CHARACTERISTICS

EN, SYNC Input High Threshold 1.2 V
EN, SYNC Input Low Threshold 0.4 V
EN, SYNC Leakage Current VIN = VEN −1 +0.1 +1 µA

THERMAL CHARACTERISTICS

Thermal Shutdown Threshold 150 °C
Thermal Shutdown Hysteresis 25 °C

1

All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC).

= 3.3 V, @ TA = TJ = −40°C to +125°C for minimum/maximum specifications and TA = 25°C for typical specifications,

OUT

1

= 0 mA to 500 mA, forced PWM mode 0.5 %

LOAD

= 2.3 V to 5.5 V, I

IN

= 0 mA, V mode = EN = VIN = 3.6 V, device not switching 38 50 µA

OUT

= 3.6 V 150 mΩ

OUT

= 0 mA to 500 mA, forced PWM mode 0.6 %

LOAD

Rev. 0 | Page 3 of 16

ADP2503/ADP2504

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ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

PVIN, VIN, SW1, SW2, VOUT, SYNC,

EN, FB
PGND to AGND −0.3 V to 0.3 V
Operating Ambient Temperature −40°C to +85°C
Operating Junction Temperature −40°C to +125°C
Storage Temperature −65°C to +150°C
Lead Temperature

Soldering (10 sec) 300°C

Vapor Phase (60 sec) 215°C

Infrared (15 sec) 220°C
ESD Human Body Model ±2000 V
ESD Charged Device Model ±1500 V
ESD Machine Model ±100 V

−0.3 V to +6 V

THERMAL RESISTANCE

θJA is specified for a device soldered to a standard JEDEC2S2P
PCB. For a typical printed circuit board of a handset, the total
thermal resistance is higher. For correct operation up to 85°C
ambient temperature the total thermal resistance must not
exceed 100 K/W.

Table 3.

Package Type

10-Lead LFCSP (QFN) 84 °C/W

θ

JA

Unit

ESD CAUTION

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

Absolute maximum ratings apply individually only, not in
combination. Unless otherwise specified, all other voltages
are referenced to GND.

Rev. 0 | Page 4 of 16

ADP2503/ADP2504

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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

1VOUT

ADP2503/

2SW2

ADP2504

3PGND

TOP VIEW

4SW1

(Not to scale)

5PVIN

*CONNECT PADDLETO GND.

Figure 2. Pin Configuration

10 FB
9AGND
8VIN
7SYNC
6EN

07475-003

Table 4. Pin Function Descriptions

Pin No. Mnemonic Description

1 VOUT Output of the ADP2503/ADP2504. Connect the output capacitor between VOUT and PGND.
2 SW2

Power Switch 2 Connection. This is the internal connection to the input PMOS and NMOS switches. Connect

SW2 to the inductor with a short, wide track.
3 PGND Power GND. Connect the input and output capacitors and the PGND pin to a PGND plane.
4 SW1

Power Switch 1 Connection. This is the internal connection to the output PMOS and NMOS switches. Connect

SW1 to the inductor with a short, wide track.
5 PVIN

Power Input. This the input to the buck-boost power switches. Place a 10 F capacitor between PVIN and

PGND as close as possible to the ADP2503/ADP2504.
6 EN Enable. Drive EN high to turn on the ADP2503/ADP2504. Bring EN low to put the part into shutdown mode.
7 SYNC The SYNC pin permits the ADP2503/ADP2504 to operate in three different modes.

Normal operation: with SYNC driven low, the ADP2503/ADP2504 operate at 2.5 MHz PWM mode for heavy

and medium loads, and moves to power save mode (PSM) mode for light loads.

Forced PWM operation: with SYNC driven high, the ADP2503/ADP2504 operate at fixed 2.5 MHz PWM mode

for all load conditions.

SYNC mode: to synchronize the ADP2503/ADP2504 switching to an external signal, drive this pin with a clock

between 2.2 MHz and 2.8 MHz. The SYNC signal must have on and off times greater than 160 ns.
8 VIN Analog Power Supply. This is the supply for the ADP2503/ADP2504 internal circuitry.
9 AGND Analog Ground.
10 FB Output Feedback. This is an input to the internal error amplifier.
EP Paddle Connect the paddle to PGND.

Rev. 0 | Page 5 of 16