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Date: 6/20/06 Rev T

SP7685, 1.2A Buck/BoostCharge Pump LED Driver

© 2006 Sipex Corporation

SP7685

DESCRIPTION

The SP7685 is a current-regulated charge pump ideal for powering high brightness LEDs for

camera flash applications. The charge pump can be set to regulate two current levels for

FLASH and TORCH modes. The SP7685 automatically switches modes between step-up

and step-down ensuring that LED current does not depend on the forward voltage. A low

current sense reference voltage (50mV) allows the use of small 0603 current sensing

resistors. The SP7685 is offered in 10-pin DFN package.

TYPICAL APPLICATION CIRCUIT

FEATURES

■ Output Current up to 1.2A

■ Up to 94% Efficiency in Torch Mode

■ Adjustable FLASH Mode Current

■ Minimum External Components: No Inductors

■ Automatic Buck/Boost Mode Switchover

■ High Frequency Operation: 2.4 MHz

■ 50mV Reference for low Loss Sensing

■ PWM Dimming Control

■ Automatic Soft Start Limits Inrush Current

■ Overvoltage Protection on Output

■ Overcurrent/temperature Protection

■ Low Ripple and EMI

■ Ultra-low Dropout Voltage in Buck Mode

■ 2.6 Second Timeout in Flash Mode

■ Space Saving RoHS Compliant, Lead Free

Package: 10-pin 3mm x 3mm DFN

APPLICATIONS

■ White LED Torch/Flash for Cell

Phones, DSCs, and Camcorders

■ White LED Backlighting

■ Generic Lighting/Flash/Strobe

Applications

■ General Purpose High Current Boost

1.2A Buck/Boost Charge Pump LED Driver

SP7685

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ENABLE

TORCH/FLASH

C1

C2

FLASH

FB

10μF

(3.0 - 4.2V)

10μF

1μF

EN

1A Flash

200mA Torch

PWF1 WLED

80KΩ

0.22Ω

O

SP7685

10 Pin DFN

10

9

8

7

6

VOUT

PGND

SGND

FB

RSET

1

2

3

4

5

VIN

C1

C2

FLASH

EN