MP3021 – 1X, 1.5X, 2X AUTO-ADJUST CHARGE PUMP WLED BACKLIGHT DRIVER

MP3021 Rev. 1.0

www.MonolithicPower.com

9

11/21/2007

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2007 MPS. All Rights Reserved.

Table 2—Setting Backlight LED Current

5-Bit

Brightness

Code

HC/LC = 0

HC/LC = 1

0

0.94

0.09

1

1.88

0.19

2

2.81

0.28

3

3.75

0.38

4

4.69

0.47

5

5.63

0.56

6

6.56

0.66

7

7.50

0.75

8

8.44

0.84

9

9.38

0.94

10

10.31

1.03

11

11.25

1.13

12

12.19

1.22

13

13.13

1.31

14

14.06

1.41

15

15.00

1.50

16

15.94

1.59

17

16.88

1.69

18

17.81

1.78

19

18.75

1.88

20

19.69

1.97

21

20.63

2.06

22

21.56

2.16

23

22.50

2.25

24

23.44

2.34

25

24.38

2.44

26

25.31

2.53

27

26.25

2.63

28

27.19

2.72

29

28.13

2.81

30

29.06

2.91

31

30.00

3.00

Figure 4—Brightness Control

CP Pin

Do not drive or force CP as it may be shorted to

ground or pumped down by the controller in the

MP3021 at any time. Excessive capacitance on

the CP node can cause the internal controller to

time out before the charge pump can be ready.

Missing the timeouts will cause excessive

pumping and a loss of efficiency. The MP3021

requires C1 and C2 be of the same value and

type.