1

Date: 12/21/04

SP7683 Four Channel Charge Pump LED Driver

© Copyright 2004 Sipex Corporation

SP7683

FEATURES

■ 2.7V to 5.5V Input Voltage Range

■ Up to 4 LEDS with matching currents

■ LEDs can be Driven from the Charge

Pump Output

■ 1X and 1.5X Mode Charge Pump

■ High Efficiency Operation

■ 1.2 MHz Switching Frequency

■ Programable LED Drive Capabliity

■ PWM Dimming Control

■ Low 0.5µA Shutdown Current

■ Soft-Start Limits Inrush Current

■ Output Overvoltage Protection

■ Thermal Shutdown Protection

■ QFN (4mm x 4mm) package

Four Channel Charge Pump Regulator LED Driver

APPLICATIONS

■ Smart Phones

■ Cell Phones

■ PDA's

■ Digital Cameras

■ MP3 Players

■ Other Portables

The SP7683 is high efficiency Charge Pump which regulates up to four white LEDs with matching

current. Based on the supply headroom available for the four precision current sinks, SP7683

automatically switches between 1X and 1.5X modes. The part powers up in 1X mode, with low

quiescent current of 70uA (typ) and remains in 1X mode as long as the LED current has not

decreased by more than 0.5%. If the current decreases, then it switches into 1.5X mode where

it regulates the lowest of the LED cathode voltages to 0.1V. Other features include soft-start, over

current protection, overvoltage protection and thermal shutdown at 140°C. Offered in 4X4 16 pin

QFN.

®

TYPICAL APPLICATION SCHEMATIC

Now Available in Lead Free Packaging

Advanced

DESCRIPTION

R1

50k - 200k

GND

R3

100k

LED_EN

U1

SP7683

R5

10k

R4

270k

R9

100k

C1

1uF

C5

1uF

C4

1uF

C2

1uF

R2

1M

D1

D2

EN

Vin

D3

D4

C3

0.1uF

R10

100k

®

®

SP7683

1

2

7

4

6

5

3

9

8

12

13

10

11

14

15 16

R

C1P

SP7683

4x4 mm

16 Pin QFN

8

7

6

5

4

3

2

1

FB

On/Off

LED3

LED4

12

11

10

9

16

15

14

13

I

SET

V

MODE

V

IN