RT6203E
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.
Table 1. Structure of the RT6203E Data Byte
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
ChkSum
D6
D5
D4
D3
D2
D1
D0
Table 2. VID Function
Code
VOUT
0.6
Code
VOUT
0.75
0.76
0.77
0.78
0.79
0.8
Code
20
VOUT
Code
VOUT
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
0.85
0.86
0.87
0.88
0.89
0.9
30
31
32
33
34
35
36
37
38
39
0.95
0.96
0.97
0.98
0.99
1
0.62
0.64
0.66
0.68
0.7
21
22
23
24
25
0.71
0.72
0.73
0.74
0.81
0.82
0.83
0.84
26
0.91
0.92
0.93
0.94
1.01
1.02
1.03
1.04
27
28
29
Code
40
VOUT
1.05
1.06
1.07
1.08
1.09
1.1
Code
50
VOUT
1.15
1.16
1.17
1.18
1.19
1.2
Code
60
VOUT
1.3
Code
70
VOUT
1.5
41
51
61
1.32
1.34
1.36
1.38
1.4
71
1.52
1.54
1.56
1.58
1.6
42
52
62
72
43
53
63
73
44
54
64
74
45
55
65
75
46
1.11
1.12
1.13
1.14
56
1.22
1.24
1.26
1.28
66
1.42
1.44
1.46
1.48
76
1.62
47
57
67
48
58
68
49
59
69
Copyright 2019 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
www.richtek.com
12
DS6203E-00 January 2019
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
