AD5243/AD5248

Data Sheet

Rev. C | Page 18 of 20

Write Bit Patterns

SCL

START BY

MASTER

SDA

0

1

1

FRAME 1

SLAVE ADDRESS BYTE

0

1

1

1

1

FRAME 2

INSTRUCTION BYTE

ACK BY

AD5243

R/W

A0

SD

X

X

X

X

1

9

D7

D6

D5

D4

D3

ACK BY

AD5243

FRAME 3

DATA BYTE

1

9

X

STOP BY

MASTER

9

D2

D1

D0

ACK BY

AD5243

X

Figure 45. Writing to the RDAC Register—AD5243

SCL

START BY

MASTER

SDA

0

1

1

FRAME 1

SLAVE ADDRESS BYTE

0

1

1

AD1 AD0

FRAME 2

INSTRUCTION BYTE

ACK BY

AD5248

R/W

A0

SD

X

X

X

X

1

9

D7

D6

D5

D4

D3

ACK BY

AD5248

FRAME 3

DATA BYTE

1

9

X

STOP BY

MASTER

9

D2

D1

D0

ACK BY

AD5248

X

Figure 46. Writing to the RDAC Register—AD5248

Read Bit Patterns

SCL

START BY

MASTER

STOP BY

MASTER

SDA

0

1

1

FRAME 1

SLAVE ADDRESS BYTE

0

1

1

1

1

FRAME 2

RDAC REGISTER

ACK BY

AD5243

R/W

D7

D6

D4

D3

D2

D1

D0

1

9

NO ACK

BY MASTER

9

D5

Figure 47. Reading Data from a Previously Selected RDAC Register in Write Mode—AD5243

SCL

START BY

MASTER

SDA

0

1

1

FRAME 1

SLAVE ADDRESS BYTE

0

1

1

AD1 AD0

FRAME 2

RDAC REGISTER

ACK BY

AD5248

R/W

D7

D6

D4

D3

D2

D1

D0

1

9

9

D5

STOP BY

MASTER

NO ACK

BY MASTER

Figure 48. Reading Data from a Previously Selected RDAC Register in Write Mode—AD5248

Multiple Devices on One Bus (Applies Only to AD5248)

Figure 49 shows four AD5248 devices on the same serial bus.

Each has a different slave address because the states of their

AD0 and AD1 pins are different. This allows each device on the

bus to be written to or read from independently. The master

device output bus line drivers are open-drain pull-downs in a

SDA

SDA

AD1

AD0

MASTER

SCL

SCL

AD5248

SDA

AD1

AD0

SCL

AD5248

SDA

AD1

AD0

SCL

AD5248

SDA

5V

5V

5V

5V

AD1

AD0

SCL

AD5248