EVAL-AD5144DBZ View Datasheet(PDF) - Analog Devices
Part Name
Description
MFG CO.
EVAL-AD5144DBZ
Analog Devices
'EVAL-AD5144DBZ' PDF : 36 Pages View PDF
Data Sheet
I2C SERIAL DATA INTERFACE
The AD5144/AD5144A have 2-wire, I2C-compatible serial
interfaces. These devices can be connected to an I2C bus as a
slave device, under the control of a master device. See Figure 5
for a timing diagram of a typical write sequence.
The AD5144/AD5144A support standard (100 kHz) and fast
(400 kHz) data transfer modes. Support is not provided for
10-bit addressing and general call addressing.
The 2-wire serial bus protocol operates as follows:
1. The master initiates a data transfer by establishing a start
condition, which is when a high-to-low transition on the
SDA line occurs while SCL is high. The following byte is
the address byte, which consists of the 7-bit slave address
and an R/W bit. The slave device corresponding to the
transmitted address responds by pulling SDA low during
the ninth clock pulse (this is called the acknowledge bit).
At this stage, all other devices on the bus remain idle while
the selected device waits for data to be written to, or read
from, its shift register.
If the R/W bit is set high, the master reads from the slave
device. However, if the R/W bit is set low, the master writes
to the slave device.
2. Data is transmitted over the serial bus in sequences of nine
clock pulses (eight data bits followed by an acknowledge bit).
The transitions on the SDA line must occur during the low
period of SCL and remain stable during the high period of SCL.
3. When all data bits have been read from or written to, a stop
condition is established. In write mode, the master pulls the
SDA line high during the tenth clock pulse to establish a stop
condition. In read mode, the master issues a no acknowledge
for the ninth clock pulse (that is, the SDA line remains high).
The master then brings the SDA line low before the tenth
clock pulse, and then high again during the tenth clock pulse
to establish a stop condition.
AD5124/AD5144/AD5144A
I2C ADDRESS
The AD5144/AD5144A each have two different device address
options available (see Table 12 and Table 13).
Table 12. 20-Lead TSSOP Device Address Selection
ADDR
7-Bit I2C Device Address
VLOGIC
0101000
No connect1 0101010
GND
0101011
1 Not available in bipolar mode (VSS < 0 V) or in low voltage mode (VLOGIC = 1.8 V).
Table 13. 24-Lead LFCSP Device Address Selection
ADDR0 Pin
ADDR1 Pin
7-Bit I2C Device Address
VLOGIC
VLOGIC
0100000
No connect1
VLOGIC
0100010
GND
VLOGIC
0100011
VLOGIC
No connect1
No connect1
No connect1
0101000
0101010
GND
No connect1 0101011
VLOGIC
No connect1
GND
GND
0101100
0101110
GND
GND
0101111
1 Not available in bipolar mode (VSS < 0 V) or in low voltage mode (VLOGIC = 1.8 V).
Rev. C | Page 25 of 36
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