Datasheet

AD5161 Data Sheet
Rev. B | Page 14 of 20
I
2
C INTERFACE
Table 7. Write Mode
S 0 1 0 1 1 0 AD0
W
A X RS SD X X X X X A D7 D6 D5 D4 D3 D2 D1 D0 A P
Slave Address Byte Instruction Byte Data Byte
Table 8. Read Mode
S 0 1 0 1 1 0 AD0 R A D7 D6 D5 D4 D3 D2 D1 D0 A P
Slave Address Byte Data Byte
S = Start Condition
P = Stop Condition
A = Acknowledge
X = Don’t Care
W
= Write
R = Read
RS = Reset wiper to Midscale 80
H
SD = Shutdown connects wiper to B terminal and open circuits
A terminal. It does not change contents of wiper register.
D7, D6, D5, D4, D3, D2, D1, D0 = Data Bits.
t
1
t
3
t
4
t
2
t
7
t
8
t
9
P S
PS
t
10
t
5
t
9
t
8
SCL
SDA
t
2
t
6
Figure 39. I
2
C Interface Detailed Timing Diagram
SCL
FRAME 1
FRAME 2
START BY
MASTER
ACK BY
AD5161
SLAVE ADDRESS BYTE
STOP BY
MASTER
INSTRUCTION BYTE
SDA
0
1
0
1
1 0 AD0 R/W
X RS X X X X X
1
91 9
D7 D6 D5 D4 D3 D2 D1
D0
ACK BY
AD5161
FRAME 3
DATA BYTE
19
ACK BY
AD5161
SD
Figure 40. Writing to the RDAC Register
NO ACK
BY MASTER
SCL
SDA
0
1 0 1 1 0 AD0 R/W
D7
D6 D5 D4 D3 D2 D1 D0
1
919
FRAME 1
FRAME 2
START BY
MASTER
ACK BY
AD5161
SLAVE ADDRESS BYTE
RDAC REGISTER
STOP BY
MASTER
Figure 41. Reading Data from a Previously Selected RDAC Register in Write Mode