AD5161 Analog Devices, AD5161 Datasheet - Page 6

• Manufacturer Part Number: AD5161
• Description: 256-Position SPI/I2C Selectable Digital Potentiometer
• Manufacturer: Analog Devices

256 Position Digital Potentiometer
I
Write Mode:
S
Read Mode:
S
S = Start Condition
P = Stop Condition
A = Acknowledge
X = Don’t Care
W = Write
R = Read
Figure 2. Detail Timing Diagram
Figure 2. Writing to the RDAC Register
Figure 3. Reading Data from a Previously Selected RDAC Register in Write Mode
REV PrB, 13 DEC’ 02
START BY
START BY
2
MASTER
MASTE R
SDA
SCL
C Interface
0
0
S DA
SCL
SCL
SDA
1
1
Slave Address Byte
Slave Address Byte
1
0
1
0
0
0
P
1
1
1
1
t
1
0
0
1
1
S
Slave Address Byte
Slave Address Byte
1
1
FRAME 1
FRAME 1
t
2
0
0
PRELIMINARY TECHNICAL DATA
1
1
A
0
A
0
t
3
0
0
W
R
AD0
AD0
t
8
t
8
A
A
R/W
R/W
t
9
ACK. BY
X
D
7
AD5161
ACK. BY
A D5161
9
9
R
S
D
6
D7
1
1
0
t
Instruction Byte
t
S
D
D
5
9
4
D6
RS
Data Byte
X
D
4
RS = Reset wiper to Midscale 80
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
D5
S D
Data Byte From Selected
- 6 -
X
D
3
D4
RDA C Register
X
t
Instruction B yte
5
FRAME 2
FRAME 2
D3
X
D
2
X
D2
X
D
1
X
D1
t
X
D
0
7
X
t
6
D0
A
A
X
B Y MASTER
NO ACK.
ACK. BY
AD5161
9
D
7
P
9
S TOP B Y
MA STER
1
D
6
X
H
X
D
5
Data Byte
D5
D
4
P
D4
D
3
t
10
FRAME 3
Data Byte
D3
AD5161
D
2
D2
D
1
D1
D
0
D0
A
ACK. BY
AD5161
9
P
STOP BY
MA STER