|Address (A) byte
|Data byte - MSDB||Data byte - LSDB|
|DB [31:24]||DB [23:16]||DB [15:8]||DB [7:0]|
After each byte is received, the DACx3204 family acknowledges the byte by pulling the SDA line low during the high period of a single clock pulse, as shown in Figure 7-21. These four bytes and acknowledge cycles make up the 36 clock cycles required for a single update to occur. A valid I2C address byte selects the DACx3204.
The command byte sets the operating mode of the selected DACx3204 device. For a data update to occur when the operating mode is selected by this byte, the DACx3204 device must receive two data bytes: the most significant data byte (MSDB) and least significant data byte (LSDB). The DACx3204 device performs an update on the falling edge of the acknowledge signal that follows the LSDB.
When using fast mode (clock = 400 kHz), the maximum DAC update rate is limited to 10 kSPS. Using fast mode plus (clock = 1 MHz), the maximum DAC update rate is limited to 25 kSPS. When a stop condition is received, the DACx3204 device releases the I2C bus and awaits a new start condition.