Datasheet

216
ATmega169A/PA/329A/PA/649A/P/3290A/PA/6490A/P [DATASHEET]
8284E–AVR–02/2013
• Differential Non-linearity (DNL): The maximum deviation of the actual code width (the interval between two
adjacent transitions) from the ideal code width (1 LSB). Ideal value: 0 LSB
Figure 23-13. Differential non-linearity (DNL).
• Quantization Error: Due to the quantization of the input voltage into a finite number of codes, a range of input
voltages (1 LSB wide) will code to the same value. Always ±0.5 LSB
• Absolute Accuracy: The maximum deviation of an actual (unadjusted) transition compared to an ideal transition
for any code. This is the compound effect of offset, gain error, differential error, non-linearity, and quantization
error. Ideal value: ±0.5 LSB
23.8 ADC Conversion Result
After the conversion is complete (ADIF is high), the conversion result can be found in the ADC Result Registers
(ADCL, ADCH).
For single ended conversion, the result is
where V
IN
is the voltage on the selected input pin and V
REF
the selected voltage reference (see Table 23-3 on page
218 and Table 23-4 on page 219). 0x000 represents analog ground, and 0x3FF represents the selected reference
voltage minus one LSB.
Output Code
0x3FF
0x000
0
V
REF
Input Voltage
DNL
1 LSB
ADC
V
IN
1024
V
REF
--------------------------=
ADC
V
POS
V
NEG
–512
V
REF
---------------------------------------------------- -=