Datasheet

Note: If the resistivity in the inductor is too high, the AV
CC
may exceed its range, V
CC
- 0.3V < AV
CC
<
V
CC
+ 0.3V.
28.6.3 ADC Accuracy Definitions
An n-bit single-ended ADC converts a voltage linearly between GND and V
REF
in 2
n
steps (LSBs). The
lowest code is read as 0, and the highest code is read as 2
n
-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 28-10. Offset Error
Output Code
V
REF
Input Voltage
Ideal ADC
Actual ADC
Offset
Error
• Gain error: After adjusting for offset, the gain error is found as the deviation of the last transition
(0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum). Ideal value: 0
LSB.
Figure 28-11. Gain Error
Output Code
V
REF
Input Voltage
Ideal ADC
Actual ADC
Gain
Error
• Integral Non-linearity (INL): After adjusting for offset and gain error, the INL is the maximum
deviation of an actual transition compared to an ideal transition for any code. Ideal value: 0 LSB.
ATmega48PA/88PA/168PA
Analog-to-Digital Converter (ADC)
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40002011A-page 323