6

Date: 12/21/04

SP7683 Four Channel Charge Pump LED Driver

© Copyright 2004 Sipex Corporation

The Low Dropout Regulator

The low dropout regulator provides matched currents into four LEDs. The current in the LED can

be programmed by an external resistor connected between the V

I

SET

pins.

I

voltage value.

Board Layout and Grounding

To obtain the best performance from the SP7683, a printed circuit board with ground plane is

required. High quality, low series resistance ceramic 0.1µF bypass capacitors should be used at

the V

located as close to the part as possible. The traces connecting the pins to these capacitors should

be made as short and wide as possible.

CIRCUIT DESCRIPTION

R1

50k - 200k

GND

D5

D6

D7

R7

D8

R8

R6

R3

100k

LED_EN

U1

SP7683

R5

20

R4

270k

R9

100k

C1

1uF

C5

1uF

C4

1uF

C2

1uF

R2

1M

D1

D2

EN

Vin

D3

D4

C3

0.1uF

R1

50k - 200k

GND

D5

D6

D7

D8

R4

100k

LED_EN

U1

SP7683

R6

R5

270k

R7

100k

C1

1uF

C5

1uF

C4

1uF

C2

1uF

R3

1M

D1

D2

EN

Vin

D3

D4

C3

0.1uF

Q1

Q2

R8

R2

D9

D10

D11

D12

®

®

SP7683

1

2

7

4

6

5

3

9

8

12

13

10

11

14

15 16

®

®

SP7683

1

2

7

4

6

5

3

9

8

12

13

10

11

14

15 16