Datasheet

89
ATtiny4/5/9/10 [DATASHEET]
8127F–AVR–02/2013
Where high ADC accuracy is required it is recommended to use ADC Noise Reduction Mode, as described in Sec-
tion 13.7 on page 87. A good system design with properly placed, external bypass capacitors does reduce the
need for using ADC Noise Reduction Mode
13.10 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 (0x00 to 0x01) compared to the ideal transition (at 0.5 LSB). Ideal
value: 0 LSB.
Figure 13-9. Offset Error
Output Code
V
REF
Input Voltage
Ideal ADC
Actual ADC
Offset
Error