Datasheet

 2018 Microchip Technology Inc. Data Sheet Complete DS40002058A-page 216
ATxmega128A1U/ATxmega64A1U
17. DAC clock noise
The system clock is visible as clock noise on the output of the DAC. Peak to peak noise is in the range 0.7mV - 1.6mV
at 2MHz and 0.05mV to 0.1mV at 32MHz. If external clock is used as system clock, the noise is up to three times
higher.
Problem fix/Workaround
Add external low-pass filter to remove the noise.
18. Internal 1V reference has noise at low temperature
The internal 1.0V reference for the ADC and DAC has increased noise at low temperatures. The noise can result in INL
numbers up to +/- 20 LSB at temperatures below 0C.
Problem fix/Workaround
For the ADC, use oversampling to reduce noise. For the DAC use external filter to reduce the noise.
39.2.2 Rev. A – K
Not sampled.