SBAS813 June 2018 ADS8688AT
PRODUCTION DATA.
The device offers two channel sequencing modes: AUTO_RST and MAN_Ch_n.
In AUTO_RST mode, the channel number automatically increments in every subsequent frame. As explained in the auto-scan sequencing control registers, the analog inputs can be selected for an automatic scan with a register setting. The device automatically scans only the selected analog inputs in ascending order. The unselected analog input channels can also be powered down for optimizing power consumption in this mode of operation. The auto-mode sequence can be reset at any time during an automatic scan (using the AUTO_RST command). When the reset command is received, the ongoing auto-mode sequence is reset and restarts from the lowest selected channel in the sequence.
In MAN_Ch_n mode, the same input channel is selected during every data conversion frame. The input command words to select individual analog channels in MAN_Ch_n mode are listed in Table 7. If a particular input channel is selected during a data frame, then the analog inputs on the same channel are sampled during the next data frame. Figure 100 shows the SDI command sequence for transitions from AUTO_RST to MAN_Ch_n mode.
Figure 101 shows the SDI command sequence for transitions from MAN_Ch_n to AUTO_RST mode. Each SDI command is executed on the next CS falling edge. A RST command can be issued at any instant during any channel sequencing mode, after which the device is placed into a default power-up state in the next data frame.