NEC V850ES/KE1+ User Manual page 392

(3) Quantization error
When analog values are converted to digital values, a ±1/2 LSB error naturally occurs. In an A/D converter, an
analog input voltage in a range of ±1/2 LSB is converted to the same digital code, so a quantization error
cannot be avoided.
Note that the quantization error is not included in the overall error, zero-scale error, full-scale error, integral
linearity error, and differential linearity error in the characteristics table.
(4) Zero-scale error
This shows the difference between the actual measurement value of the analog input voltage and the
theoretical value (1/2 LSB) when the digital output changes from 0......000 to 0......001.
392
CHAPTER 13 A/D CONVERTER
Figure 13-13. Quantization Error
1 ...... 1
Quantization error
1/2 LSB
1/2 LSB
0 ...... 0
0
Analog input
Figure 13-14. Zero-Scale Error
111
Ideal line
100
Zero-scale error
011
010
001
000
-1 0 1 2
Analog input (LSB)
User's Manual U16896EJ2V0UD
AV
REF0
3 AV
REF0