EVAL-AD5398AEBZ AD [Analog Devices], EVAL-AD5398AEBZ Datasheet - Page 11

• Manufacturer Part Number: EVAL-AD5398AEBZ
• Description: 120 mA, Current Sinking, 10-Bit, I2C DAC
• Manufacturer: AD [Analog Devices]

DATA FORMAT
Data is written to the AD5398A high byte first, MSB first, and is
shifted into the 16-bit input register. After all data is shifted in,
data from the input register is transferred to the DAC register.
Because the DAC requires only 10 bits of data, not all bits of the
input register data are used. The MSB is reserved for an active-
high, software-controlled, power-down function.
Table 6. Data Format
Serial Data-
Words
Serial Data Bits
Input Register
Function
1
SDA
SDA
SCL
SCL
PD = soft power-down; X = unused/don’t care; and D7 to D0 = DAC data.
START BY
START BY
MASTER
MASTER
1
1
1
0
0
0
0
Bit
15
SD7
PD
R15
ADDRESS BYTE
ADDRESS BYTE
0
0
SERIAL BUS
SERIAL BUS
FRAME 1
FRAME 1
1
1
Bit
14
SD6
R14
X
1
1
Bit
13
SD5
D9
R13
X
X
X
X
R/W
R/W
Bit
12
SD4
R12
D8
AD5398A
ACK BY
High Byte
AD5398A
ACK BY
9
9
Bit
11
SD3
R11
D7
PD
PD
1
1
X
X
Figure 18. Write Operation
Figure 19. Read Operation
Bit
10
SD2
R10
D6
D9
D9
MOST SIGNIFICANT
MOST SIGNIFICANT
Rev. 0 | Page 11 of 16
DATA BYTE
DATA BYTE
D8
D8
FRAME 2
FRAME 2
Bit
9
SD1
R9
D5
D7
D7
D6
D6
The data format is shown in Table 6. When referring to this table,
note that Bit 14 is unused; Bit 13 to Bit 4 correspond to the DAC
data bits, D9 to D0; and Bit 3 to Bit 0 are unused.
During a read operation, data is read in the same bit order.
Bit
8
SD0
R8
D4
D5
D5
D4
D4
Bit
7
SD7
R7
D3
AD5398A
AD5398A
ACK BY
ACK BY
1
1
Bit
6
SD6
R6
D2
D3
D3
D2
D2
Bit
5
SD5
R5
D1
D1
D1
LEAST SIGNIFICANT
LEAST SIGNIFICANT
D0
D0
DATA BYTE
DATA BYTE
Bit
4
SD4
R4
D0
FRAME 3
FRAME 3
Low Byte
X
X
Bit
3
SD3
R3
X
X
X
X
X
Bit
2
SD2
R2
X
X
AD5398A
X
ACK BY
AD5398A
ACK BY
AD5398A
9
9
Bit
1
SD1
R1
X
STOP BY
STOP BY
MASTER
MASTER
Bit
0
SD0
R0
X