9

Date: 5/5/04

SP6682 High Efficiency Charge Pump Regulator for White LEDs

© Copyright 2004 Sipex Corporation

are the forward voltage and operating current of

n is the boost ratio (X1.5 or X2)

SP6682 High Voltage White LED Driver

The SP6682 can also be configured as a high

voltage boost converter to drive more than 10

white LEDs. Figure 15 shows the schematic of

this application as well as actual data showing

efficiency of > 85%. By using an external induc-

tor, MOSFET and diode, high output voltage

can be generated to drive 12 white LEDs (2

branches, each branch has 6 white LEDs in

series). The current through the white LEDs is

determined by:

70

75

80

85

90

95

100

2.7

3.0

3.3

3.6

3.9

4.2

D11

X5R Ceramic

D3

SOT23

R2

15

25V

L1 LQH32CN4R7M11

4.7uH

D12

D8

DS SCHOTTKY MBR0530

D4

Q1

Ceramic

EN/PWM

R1

15

D6

C1

10uF

D9

D7

C3 X5R

2.2uF 25V

D10

D2

R3

1M

ILED = VFB/R1 = 20mA

SP6682

1

2

7

6

5

4

3

8

9

10

V

OUT

C1P

C2N

EN/PWM

FB

V

MODE

V

IN

GND

C1N

C2P

D1

SI1304

D5

Vin: 2.7-4.2V

Figure 15. Using SP6682 as a High Voltage White LED Driver

APPLICATION INFORMATION

PINOUTS

C1P

FB

SP6682

10 Pin MSOP

1

2

3

4

5

10

9

8

7

6

C2P

C1N

GND

C2N

EN/PWM

SP6682

10 Pin DFN

10

9

8

7

6

1

2

3

4

5

C2P

C1N

GND

C2N

EN/PWM

V

OUT

C1P

V

IN

V

MODE

FB