Rainbow Electronics ATmega3290P_V - Manual (Page 211)

211
ATmega329/3290/649/6490
2552H–AVR–11/06
Figure 92. ADC Power Connections
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 93. Offset Error
VCC
GND
100nF
Analog Ground Plane
(ADC0) PF0
(ADC7) PF7
(ADC1) PF1
(ADC2) PF2
(ADC3) PF3
(ADC4) PF4
(ADC5) PF5
(ADC6) PF6
AREF
GND
AVCC
52
53
54
55
56
57
58
59
60
61 61
62 62
63 63
64 64
1
51
LCDCAP
PA0
10 μΗ
Output Code
V
REF
Input Voltage
Ideal ADC
Actual ADC
Offset
Error