8.5.1.12 Single-Shot Mode

The single-shot mode is enabled by setting the SINGLE_SHOT bit in the CONFIG1 register to '1'. In single-shot mode, the ADS1291, ADS1292, and ADS1292R perform a single conversion when the START pin is taken high or when the START opcode command is sent. As seen in Figure 50, when a conversion is complete, DRDY goes low and further conversions are stopped. Regardless of whether the conversion data are read or not, DRDY remains low. To begin a new conversion, take the START pin low and then back high, or transmit the START opcode again. When switching from continuous mode to pulse mode, make sure the START signal is pulsed or issue a STOP command followed by a START command.

This conversion mode is provided for applications that require non-standard or non-continuous data rates. Issuing a START command or toggling the START pin high resets the digital filter, effectively dropping the data rate by a factor of four. Note that this mode leaves the system more susceptible to aliasing effects, requiring more complex analog anti-aliasing filters at the inputs. Loading on the host processor increases because it must toggle the START pin or send a START command to initiate a new conversion cycle.

Figure 51. DRDY with No Data Retrieval in Single-Shot Mode