2.2 References

  • External Reference
  • Internal Reference
    • 1.024V
    • 2.048V
    • 2.500V
    • 4.096V
    • VDD

The reference voltage for the ADC (VREF) controls the conversion range of the ADC. External reference and five internal references are available.

ADC0.CTRLC = ADC_REFSEL_1024MV_gc;  /* Reference selection 1.024V */

Except for VDD, the internal reference voltages are generated from an internal band gap reference. VDD must be at least 0.5V higher than the selected band gap reference voltage.

Changing the reference while a conversion is ongoing will corrupt the output.