31.3.3 Sleep Mode Operation
If the Run in Standby bit (RUNSTDBY) in the Control A register (DAC.CTRLA) is written to '1' and CLK_PER is available, the DAC will continue to operate in Standby Sleep mode. If RUNSTDBY bit is '0', the DAC will stop the conversion in Standby Sleep mode.
If the conversion is stopped in Standby Sleep mode, the DAC and the output buffer are disabled to reduce power consumption. When the device is exiting Standby Sleep mode, the DAC and the output buffer (if configured by OUTEN=1 in DAC.CTRLA) are enabled again. Therefore, a certain start-up time is required before a new conversion is initiated.
In Power-Down Sleep mode, the DAC and output buffer are disabled to reduce the power consumption.