Atmel AVR ATmega88PA Specification Sheet page 4

1.1.7 AV
CC
1.1.8 AREF
1.1.9 ADC7:6 (TQFP and QFN/MLF Package Only)
8161DS–AVR–10/09
The various special features of Port D are elaborated in
82.
AV is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally
CC
connected to V , even if the ADC is not used. If the ADC is used, it should be connected to V
CC
through a low-pass filter. Note that PC6..4 use digital supply voltage, V
AREF is the analog reference pin for the A/D Converter.
In the TQFP and QFN/MLF package, ADC7:6 serve as analog inputs to the A/D converter.
These pins are powered from the analog supply and serve as 10-bit ADC channels.
ATmega48PA/88PA/168PA/328P
"Alternate Functions of Port D" on page
CC
.
CC
4