Technical Note

7/12

www.rohm.com

2011.06 - Rev.B

© 2011 ROHM Co., Ltd. All rights reserved.

BD1601MUV

●

Function Description

(1) LED driver

▪ UPIC interface

BD1601MUV is a single line digital interface control (Uni-port Interface Control=UPIC) that can control the power

ON/OFF and LED current value through the EN pin only. The LED current increments by about 0.5mA depending on the

number of leading edges. When the number of leading edge is added at the maximum output current of 30mA (64

leading edges), the current is almost equal to 0.5mA at startup time. To maintain any output current, the EN pin must be

kept at “H” level. To power off, the EN pin must be kept at “L” level for more than 640µsec.

EN

(Internal)

State

C1

C2

C3

C4

C3

1.4mA

1.4mA 1.9mA

C5

30mA

29.5mA

C63

C64

Soft Start

0.5mA

2.3mA

0.9mA

C1

C2

OFF

OFF

Fig.16 Brightness Control Method

EN

Fig.17 UPIC Interface

▪ LED current level

The LED current state can be changed by the EN control signal. When the current level is Cn, the basic LED current

(ILED) can be obtained from the following expression (where, n indicates a state number).

State

Output current

[mA]]

State

Output current

[mA]

State

Output current

[mA]

State

Output current

[mA]

C1

0.5

C14

8.0

C33

15.5

C49

23.0

C2

0.9

C18

8.4

C34

15.9

C50

23.4

C3

1.4

C19

8.9

C35

16.4

C51

23.9

C4

1.9

C20

9.4

C36

16.9

C52

24.4

C5

2.3

C21

9.8

C37

17.3

C53

24.8

C6

2.8

C22

10.3

C38

17.8

C54

25.3

C7

3.3

C23

10.8

C39

18.3

C55

25.8

C8

3.8

C24

11.3

C40

18.8

C56

26.3

C9

4.2

C25

11.7

C41

19.2

C57

26.7

C10

4.7

C26

12.2

C42

19.7

C58

27.2

C11

5.2

C27

12.7

C43

20.2

C59

27.7

C12

5.6

C28

13.1

C44

20.6

C60

28.1

C13

6.1

C29

13.6

C45

21.1

C61

28.6

C14

6.6

C30

14.1

C46

21.6

C62

29.1

C15

7.0

C31

14.5

C47

22.0

C63

29.5

C16

7.5

C32

15.0

C48

22.5

C64

30.0