
173
8008H–AVR–04/11
ATtiny48/88
Where high ADC accuracy is required it is recommended to use ADC Noise Reduction Mode, as
is above 1 MHz, or when the ADC is used for reading the internal temperature sensor, as
bypass capacitors does reduce the need for using ADC Noise Reduction Mode
17.10 ADC Accuracy Definitions
An n-bit single-ended ADC converts a voltage linearly between GND and V
REF in 2
n steps
(LSBs). The lowest code is read as 0, and the highest code is read as 2
n-1.
Several parameters describe the deviation from the ideal behavior:
Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition
(at 0.5 LSB). Ideal value: 0 LSB.
Figure 17-10. Offset Error
Output Code
VREF Input Voltage
Ideal ADC
Actual ADC
Offset
Error