ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 223

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

23.7.3
8285D–AVR–06/11
ADC Accuracy Definitions
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
An n-bit single-ended ADC converts a voltage linearly between GND and V
(LSBs). The lowest code is read as 0, and the highest code is read as 2
Several parameters describe the deviation from the ideal behavior:
• Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition (at
Figure 23-10. Offset Error
• Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the last
Figure 23-11. Gain Error
• Integral Non-linearity (INL): After adjusting for offset and gain error, the INL is the maximum
0.5 LSB). Ideal value: 0 LSB.
transition (0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum).
Ideal value: 0 LSB
deviation of an actual transition compared to an ideal transition for any code. Ideal value: 0
LSB.
Output Code
Output Code
Offset
Error
Gain
Error
V
V
REF
REF
Input Voltage
Input Voltage
Ideal ADC
Actual ADC
n
Ideal ADC
Actual ADC
-1.
REF
in 2
n
steps
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