3.2.1 ADC Input Selection

V_bg (V_REF) can be selected as the ADC input per the table below, from the ADMUX registers of the ADC at ATmega328PB.

Table 3-1. ADC Input Selected
REFS[1:0]	Voltage reference selection
0	AREF, internal V_REF turned OFF
1	AVCC with external capacitor at AREF pin
10	Reserved
11	Internal 1.1V voltage reference with external capacitor at AREF pin

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