Dual 750 mA LED Flash Driver

Data Sheet

ADP1660

Rev. 0

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FEATURES

Ultracompact solution

Small, 2 mm × 1.7 mm, 12-ball WLCSP package

Smallest footprint, 1 mm height, 1 μH power inductor

LED current source for local LED grounding

Simplified routing to and from LEDs

Improved LED thermal dissipation

Synchronous 3 MHz PWM boost converter, no external diode

High efficiency: 90% peak

Reduces high levels of input battery current during flash

Limits battery current drain in torch mode

Currents up to 750 mA in flash mode per LED

with ±7% accuracy for currents above 100 mA

Torch mode

Programmable dc battery current limit

Programmable flash timer up to 1600 ms

Low battery mode to reduce LED current automatically

Device control

External STROBE and torch input pins

Transmitter mask (TxMASK) input

Safety features

Thermal overload protection

Inductor fault detection

LED short-circuit/open-circuit protection

APPLICATIONS

Camera-enabled cellular phones and smartphones

Digital still cameras, camcorders, and PDAs

FUNCTIONAL BLOCK DIAGRAM

ADP1660

10µF

1.0µH

INPUT VOLTAGE = 2.7V TO 5.0V

VOUT

PGND

SW

STROBE

10µF

LED1

LED2

EN

SGND

SCL

SDA

TORCH/

TxMASK

GPIO

UP TO

750mA

UP TO

750mA

VIN

Figure 1.

LED2

DIGITAL

INPUT/

OUTPUT

Li-ION+

PGND

C1

L1

INDUCTOR

LED1

C2

Figure 2. PCB Layout

GENERAL DESCRIPTION

The ADP1660 is a very compact, highly efficient, dual white LED

flash driver for high resolution camera phones that improves

picture and video quality in low light environments. The device

integrates a programmable 1.5 MHz or 3.0 MHz synchronous

750 mA current sources. The high switching frequency enables

the use of a tiny, 1 mm high, low cost, 1 μH power inductor, and

the parallel current sources permit LED cathode grounding for

thermally enhanced, low EMI, and compact layouts.

The LED driver maximizes efficiency over the entire battery voltage

range to maximize the input-power-to-LED-power conversion

and minimize battery current draw during flash events.

A programmable dc battery current limit safely maximizes

LED current for all LED forward voltage and battery voltage

conditions.

A TxMASK input enables fast reduction of the flash LED

currents and battery current during a power amplifier current

timers and currents and to read back status bits for operation

monitoring and safety control.

The ADP1660 comes in a compact, 12-ball, 0.5 mm pitch

WLCSP package and operates within specification over the

full −40°C to +125°C junction temperature range.