Datasheet

Table Of Contents
211
2570N–AVR–05/11
ATmega325/3250/645/6450
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.
23.7 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 213 and Table 23-4 on page 214). 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
---------------------------------------------------- -=