Rainbow Electronics ATmega128RFA1 - Manual (Page 423)

423
8266A-MCU Wireless-12/09
ATmega128RFA1
Figure 27-14. Integral Non-linearity (INL)
Output Code
V
REF
Input Voltage
Ideal ADC
Actual ADC
INL
• 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 27-15. Differential Non-linearity (DNL)
Output Code
0x3FF
0x000
0 V
REF
Input Voltage
DNL
1 LSB
• 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. It is
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.
27.8 ADC Conversion Result
After the conversion is complete (ADIF is high), the conversion result can be found in
the ADC Result Registers (ADCL, ADCH).