2.5.4 Inaccurate ADC Conversion in Differential Mode with 200x Gain

With AVCC < 3.6V, random conversions will be inaccurate. The typical absolute accuracy may reach 64 LSBs.

Work Around

Use AVCC ≥ 3.6V.

Affected Silicon Revisions

ATmega640
Rev. ARev. B
XX
ATmega1280/1281
Rev. ARev. B
X-