8-bit AVR Microcontroller

Block Diagram

The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is held at a constant level during conversion.

Internal reference voltage of nominally 1.1V, 2.2V, and 4.3V is provided on-chip. Alternatively, VCC can be used as reference voltage for single ended channels.

Figure 1. Analog to Digital Converter Block Schematic Operation