Datasheet

90
ATtiny13
2535E–AVR–10/04
Figure 51. Differential Non-linearity (DNL)
• 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. 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.
ADC Conversion Result After the conversion is complete (ADIF is high), the conversion result can be found in
the ADC Result Registers (ADCL, ADCH).
For single ended conversion, the result is
where V
IN
is the voltage on the selected input pin and V
REF
the selected voltage refer-
ence (see Table 37 on page 91 and Table 38 on page 91). 0x000 represents analog
ground, and 0x3FF represents the selected reference voltage minus one LSB.
ADC Multiplexer Selection
Register – ADMUX
• Bit 7 – Res: Reserved Bit
This bit is reserved bit in the ATtiny13 and will always read as zero.
• Bit 6 – REFS0: Reference Selection Bit
Output Code
0x3FF
0x000
0
V
REF
Input Voltage
DNL
1 LSB
ADC
V
IN
1024⋅
V
REF
--------------------------=
Bit 76543210
– REFS0 ADLAR – – – MUX1 MUX0 ADMUX
Read/Write R R/W R/W R R R R/W R/W
Initial Value00000000