Rainbow Electronics ATmega3290P_V - Manual (Page 213)

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ATmega329/3290/649/6490
2552H–AVR–11/06
• 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 96. 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.
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 refer-
ence (see Table 95 on page 215 and Table 96 on page 216). 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
----------------------------------------------------- =