Compact, High Efficiency, High Power

Flash/Torch LED Driver with Dual Interface

ADP1653

Rev. A

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

responsibilityis assumedbyAnalogDevicesforitsuse,norforanyinfringements of patents or other

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

www.analog.com

Fax: 781.461.3113

©2007 Analog Devices, Inc. All rights reserved.

Rev. A

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

responsibilityis assumedbyAnalogDevicesforitsuse,norforanyinfringements of patents or other

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

www.analog.com

Fax: 781.461.3113

©2007 Analog Devices, Inc. All rights reserved.

FEATURES

Small 6.4 mm × 7.2 mm solution

2.2 μH power inductor

92% peak efficiency

Tx masking within 50 μs

2.1 A, 12 V power switch

Programmable flash and torch current

Up to 200 mA in torch mode

Up to 500 mA in flash mode

Programmable indicator LED current up to 20 mA

Programmable timer register: up to 820 ms flash timeout

2.75 V to 5.5 V input voltage range

Low noise, 1.2 MHz PWM operation

Safety features

Interrupt output pin

Fault condition register

Short-circuit protection

Output overvoltage protection

Thermal overload protection

Integrated current limit and soft start

Small 3 mm × 3 mm, 16-lead LFCSP footprint

APPLICATIONS

Camera-enabled cellular phones, smart phones

Digital still cameras, camcorders, PDAs

GENERAL DESCRIPTION

The ADP1653 is a very compact, high efficiency, high power,

camera-flash LED driver optimized for cellular phones. The

device’s high efficiency and dynamic LED current control

improve flash brightness and picture quality in dimly lit

environments. Efficiency peaks at 92% and is higher than

charge pump solutions over the Li-Ion battery range.

The device has a dual-mode interface that is configurable to 2-bit

currents are programmable with external resistors or through the

offers an input to reduce flash LED current in less than 50 μs,

referred to as the Tx mask. Tx masking reduces battery stress by

scaling back flash LED current during an RF transmission.

The ADP1653 solution requires only four external components

grates multiple safety features such as soft start, flash timeout,

output current limit, thermal protection, and overvoltage

protection.

The ADP1653 operates over the −40°C to +125°C junction

temperature range.

TYPICAL OPERATING CIRCUIT

16

15

14

13

5

6

7

8

12

11

10

9

1

2

3

4

ADP1653

4.7µF

4.7µF

ONE

OR

TWO

LEDs

UP TO 10.2V

2.2µH

INPUT VOLTAGE = 2.75V TO 5.5V

TxMASK

OPTIONAL

SETT

SETF

CTRL1/SCL

CTRL0/SDA

EN

STR

LX

SETI ILED

OUT

GND

PGND

INTF

HPLED

INT

OFF

ON

OFF

ON

Figure 1.

PCB LAYOUT

ADP1653

R5

R4

D1

C1

C2

INDUCTOR

LI-ION +

GND

L1

INPUT CAPACITOR

OUTPUT CAPACITOR

SCHOTTKY DIODE

PGND

7.2mm

TO WHITE

LEDs

FROM WHITE

LEDs

L = FDSE0312-2R2

CIN = GRM219R61A475K

D1 = BAT20J

COUT = GRM21BR61C475K

6.4mm

OPTIONAL (Tx MASK ONLY)

Figure 2.