AD5339 Analog Devices, AD5339 Datasheet - Page 18

• Manufacturer Part Number: AD5339
• Description: 2.5 V to 5.5 V, 250 µA, 2-Wire Interface, Dual Voltage Output,12-Bit DACs
• Manufacturer: Analog Devices

Specifications of AD5339

• Resolution (bits): 12bit
• Dac Update Rate: 14.8kSPS
• Dac Settling Time: 8µs
• Max Pos Supply (v): +5.5V
• Single-supply: Yes
• Dac Type: Voltage Out
• Dac Input Format: I2C/Ser 2-wire

AD5337/AD5338/AD5339
READ OPERATION
When reading data back from the AD5337/AD5338/AD5339
DACs, the user begins with an address byte (R/ W = 0), after
which the DAC acknowledges that it is prepared to receive data
by pulling SDA low. This address byte is usually followed by the
pointer byte, which is also acknowledged by the DAC. Then, the
master initiates another start condition (repeated start) and the
address is resent with R/ W = 1. This is acknowledged by the
DAC indicating that it is prepared to transmit data. Two bytes
of data are then read from the DAC as shown in Figure 34. A
stop condition follows.
SDA
SDA
SDA
SCL
SCL
SCL
CONDITION
MASTER
START
BY
CONDITION
REPEATED
MASTER
START
0
BY
MSB
0
0
0
0
LEAST SIGNIFICANT DATA BYTE
ADDRESS BYTE
ADDRESS BYTE
0
1
1
1
0
1
A0
0
A0
R/W
LSB
Figure 34. Read Sequence
AD533x
Rev. C | Page 18 of 28
ACK
BY
MASTER
R/W
ACK
NO
BY
AD533x
MSB
ACK
X
BY
CONDITION
MASTER
Note that in a read sequence, data bytes are the same as those in
the write sequence, except that don’t cares are read back as 0s.
However, if the master sends an ACK and continues clocking
SCL (no stop is sent), the DAC retransmits the same two bytes
of data on SDA. This allows continuous read back of data from
the selected DAC register. Alternatively, the user can send a
start followed by the address with R/ W = 1. In this case, the
previously loaded pointer settings are used and read back of
data can begin immediately.
STOP
MSB
X
BY
POINTER BYTE
DATA BYTE
LSB
AD533x
ACK
BY
LSB
MASTER
ACK
BY