ATtiny88 datasheet(169/266 Pages) ATMEL

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8008C–AVR–03/09

ATtiny48/88

• Differential Non-linearity (DNL): The maximum deviation of the actual code width (the interval

between two adjacent transitions) from the ideal code width (1 LSB). Ideal value: 0 LSB.

Figure 17-13. 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.

17.11 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 VREF the selected voltage reference (see

Table 17-3 on page 170 and Table 17-4 on page 171). 0x000 represents analog ground, and

0x3FF represents the selected reference voltage minus one LSB.

17.12 Temperature Measurement

The temperature measurement is based on an on-chip temperature sensor that is coupled to a

single-ended ADC8 channel. Selecting the ADC8 channel by writing the MUX3..0 bits in ADMUX

Output Code

0x3FF

0x000

VREF Input Voltage

DNL

1 LSB

ADC

1024

⋅

REF

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ATtiny88 数据表(PDF) 169 Page - ATMEL Corporation