7

Date: 3/31/06 RevG

SP6683 1X/1.5X Charge Pump LED Driver for Flash or Backlight

© Copyright 2006 Sipex Corporation

APPLICATION INFORMATION

Camera Flash Application

Camera Flash/Torch Application

Configuring as Cellphone Camera

Flash Driver

SP6683 is capable of delivering up to 200mA

current, which is perfect to drive the most

common LEDs in today's market.

It is

designed to work in the cell phone camera

flash which powers up directly from the

Lithium-Ion battery.

Configuring as LCD Backlight

The SP6683 is able to efficiently drive up to

eight

20mA white LEDs in parallel and

maintain a constant brightness over a very

wide operating voltage range (2.7V to 5.5V)

Programming X1 or X1.5 Operating Mode

For simplest application circuitry, SP6683's

X1.5 mode.

The SP6683 can automatically

change from X1 mode to X1.5 to maximize

efficiency. To use this feature, divider resistors

should be chosen according to the specific ap-

plication, as shown below.

V

IN

V

IN

C2

GND

4

V

MODE

R1

SP6683

8

R2

3

Programming the Vmode Resistors

Configuring as Camera Flash + Torch Driver

The SP6683 can be configured as a flash/

torch LED driver which in some applications

require constant torch current used for mo-

tion pictures (i.e. movie mode).

LCD Backlight Application

SP6683

1 Vout

C1P

2

Vin

3

Vmode

4

FB

5

10

C2P

C1N 9

GND 8

C2N 7

EN/PWM 6

EN/PWM

C1

2.2uF

6.3V/0603

C2

1uF

6.3V/0603

C4

6.3V/0603

C3

1uF

6.3V/0603

LED1

Rb

1.5 ohm

1% / 0603

Vin

2.7V~4.2V

Io=Vfb/Rb

2.2uF

SP6683

C1P

FB

®

C2P

C1N

GND

C2N

EN/PWM

1

2

3

4

5

10

9

8

7

6

C2

1µF

C4

1µF

C5

1µF

R6

20

C1

1µF

Lithium

-Ion

ENABLE

White

LED

20

2.7 -

4.2V

SP6683

C1P

FB

®

C2P

C1N

GND

C2N

EN/PWM

1

2

3

4

5

10

9

8

7

6

C2

C4

C5

C1

Lithium

Ion

ENABLE

D1

White

LED

R1

1M

Ω

3.0 - 4.2V

R2

1M

Ω

FLASH

1µF

2.2µF

1µF

2.2µF

Torch Mode: Vf=3.2V , Enable = High, FLASH = Low.

Flash Mode: Vf=3.3V, Enable = High, FLASH = High.

0

50

100

150

200

250

300

350

400

3.2

3.4

3.6

3.8

4.0

4.2

Vin (V)

Flash Mode

Torch Mode

Figure 13. I