AL3050

Document number: DS38578 Rev. 2 - 2

11 of 16

www.diodes.com

July 2016

© Diodes Incorporated

AL3050

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FB Voltage (mV)

D4

D3

D2

D1

D0

0

0

0

0

0

0

0

1

5

0

0

0

0

1

2

8

0

0

0

1

0

3

11

0

0

0

1

1

4

14

0

0

1

0

0

5

17

0

0

1

0

1

6

20

0

0

1

1

0

7

23

0

0

1

1

1

8

26

0

1

0

0

0

9

29

0

1

0

0

1

10

32

0

1

0

1

0

11

35

0

1

0

1

1

12

38

0

1

1

0

0

13

44

0

1

1

0

1

14

50

0

1

1

1

0

15

56

0

1

1

1

1

16

62

1

0

0

0

0

17

68

1

0

0

0

1

18

74

1

0

0

1

0

19

80

1

0

0

1

1

20

86

1

0

1

0

0

21

92

1

0

1

0

1

22

98

1

0

1

1

0

23

104

1

0

1

1

1

24

116

1

1

0

0

0

25

128

1

1

0

0

1

26

140

1

1

0

1

0

27

152

1

1

0

1

1

28

164

1

1

1

0

0

29

176

1

1

1

0

1

30

188

1

1

1

1

0

31

200

1

1

1

1

1

Table 1. 32-Step Digital Dimming Setting

The digital dimming interface is based on a master-slave structure, where the master is typically a microcontroller or application processor. Figure

3 and Table 2 give an overview of the protocol. The protocol consists of a device specific address byte and a data byte. The device specific

address byte is fixed to 58 hex. The data byte consists of five bits for information, two address bits ("00"), and the RFA bit. The RFA bit set to high

indicates the Request for Acknowledge condition. The Acknowledge condition is only applied if the protocol was received correctly. The advantage

of single wire digital dimming compared with other on pin interfaces is that its bit detection is in a large extent independent from the bit

transmission rate. It can automatically detect bit rates between 1.1kBit/sec and up to 100kBit/sec.

DA6

1

DA7

0

DA5

1

DA4

1

DA3

0

Start

0

1

DA2 DA1

0

DA0 EOS

A1

RFA

A0

D4

D3

Start

D2

D1

D0

EOS

DATA IN

DATA OUT

ACK

DATABYTE

Device Address

Figure 3. Single Wire Digital Protocol Overview