RT6203E

12

DS6203E-00 January 2019

www.richtek.com

©

Copyright 2019 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Application Information

I2C Interface Function

The RT6203E implements a subset of the I2C standard and provides a complete transaction command with a address

byte followed by a single 8-bit data byte. Becasue there is no register address, the read function and multi-byte data

transfer are not supported in this subset function. If the RT6203E fails to acknowledge for address byte or data byte, the

master should issue a STOP command of ERROR and try again.

The 7-bit address of the RT6203E with a WRITE operation bit can become an 8 bits I2C address byte. (Address =

0b01101000). Table 1 is the structure of the RT6203E Data Byte. Bit0 to Bit6 are the 7-bit code for one of 77 output

voltage and special function. After the soft-start time, Master can sent 8 bits data to control the VOUT of the RT6203E.

The voltages can be selected from Table 2 and Table 3 shows how to use special function. The bit7 is check-sum bit and

Master should set this bit to be the Exclusive-OR of [Bit6:Bit0]. In other words, the sum is even. If not, the RT6203E will

not send an ACK bit.

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

ChkSum

D6

D5

D4

D3

D2

D1

D0

Table 1. Structure of the RT6203E Data Byte

Table 2. VID Function

Code

VOUT

Code

VOUT

Code

VOUT

Code

VOUT

0

0.6

10

0.75

20

0.85

30

0.95

1

0.62

11

0.76

21

0.86

31

0.96

2

0.64

12

0.77

22

0.87

32

0.97

3

0.66

13

0.78

23

0.88

33

0.98

4

0.68

14

0.79

24

0.89

34

0.99

5

0.7

15

0.8

25

0.9

35

1

6

0.71

16

0.81

26

0.91

36

1.01

7

0.72

17

0.82

27

0.92

37

1.02

8

0.73

18

0.83

28

0.93

38

1.03

9

0.74

19

0.84

29

0.94

39

1.04

Code

VOUT

Code

VOUT

Code

VOUT

Code

VOUT

40

1.05

50

1.15

60

1.3

70

1.5

41

1.06

51

1.16

61

1.32

71

1.52

42

1.07

52

1.17

62

1.34

72

1.54

43

1.08

53

1.18

63

1.36

73

1.56

44

1.09

54

1.19

64

1.38

74

1.58

45

1.1

55

1.2

65

1.4

75

1.6

46

1.11

56

1.22

66

1.42

76

1.62

47

1.12

57

1.24

67

1.44

48

1.13

58

1.26

68

1.46

49

1.14

59

1.28

69

1.48