Jul16-07 RevP

SP7686: 500mA LED Driver



2007 Sipex Corporation

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FEATURES

Output current up to 500mA

Up to 94% efficiency in 1x mode

Built-in LED current setting DAC

One line serial interface

2.4MHz switching frequency

FB Reference voltage adjusts in 10mV steps

from 60mV to 360mV

DAC signal shutdown control

Power-saving shutdown mode of 10nA

PWM brightness control for DAC

Fast turn-on (<150µs)

3.5s Timeout function to protect the LED

Thermal shutdown protection

Built-in over-voltage and over-current protection

Fixed output versions available (SP7686A)

Automatic soft start limits in-rush current

Lead Free, RoHS Compliant Package:

Space saving 8-pin 2x3mm DFN

DESCRIPTION

The SP7686 is a current regulated charge pump ideal for powering high-brightness LEDs for camera FLASH

applications of up to 500mA. The charge pump automatically switches between step-up and step-down modes

ensuring that the LED current does not depend on the forward voltage. A low current sense reference voltage

(60mV to 360mV) allows the use of small 0603 current sensing resistors. The SP7686 has a DAC programmable

feedback reference voltage allowing the user to precisely set FLASH and TORCH output current levels, while the

fixed version SP7686A has set levels of FLASH and TORCH reference voltage. Both parts have over-voltage, over-

current, over-temperature and FLASH time-out protection features. The SP7686 is offered in the 2x3mm 8-pin DFN package.

TYPICAL APPLICATION CIRCUITS

SP7686/7686A

Constant Current Flash Driver in DFN 2mm x 3mm

CTRL

VIN

0.22uF

VIN

10uF

2.2uF

SP7686

0.68

500m

A

CTRL

FB

C1

C2

C2

PGND

SGND

SGND

VIN

0.22uF

FLASH

VIN

10uF

2.2uF

SP7686A

500m

A

FLAS

FB

EN

EN

PGND

C1

C2

C2

0.33

Solved by

TM

SP7686

SP7686A