ATMEGA8_08 Datasheet, PDF (203/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

Figure 96. ADC Power Connections
ATmega8(L)
ADC Accuracy
Definitions
PC1 (ADC1)
PC0 (ADC0)
ADC7
GND
AREF
ADC6
AVCC
PB5
An n-bit single-ended ADC converts a voltage linearly between GND and V_REF in 2ⁿ steps
(LSBs). The lowest code is read as 0, and the highest code is read as 2ⁿ-1.
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 0.5 LSB). Ideal value: 0 LSB.
Figure 97. Offset Error
Output Code
2486T–AVR–05/08
Offset
Error
Ideal ADC
Actual ADC
V_REF Input Voltage
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