CHAPTER 12 A/D CONVERTER
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User’s Manual U14359EJ4V0UM
(3) Quantization error
This is an error of
±
1/2 LSB that inevitably occurs when an analog value is converted into a digital value.
Because the A/D converter converts analog input voltages in a range of
±
1/2 LSB into the same digital codes,
quantization error is unavoidable.
This error is not included in the total error, zero-scale error, full-scale error, integral linearity error, and
differential linearity error in the characteristic table.
Figure 12-19. Quantization Error
Quantization error
1......1
0......0
0
AV
REF
Analog input
Digital output
1/2 LSB
1/2 LSB
(4) Zero-scale error
This is a difference between the actually measured analog input voltage and its theoretical value when digital
output changes from 0…000 to 0…001 (1/2 LSB).
Figure 12-20. Zero-Scale Error
AV
REF
Analog input (LSB)
Digital output (lower 3 bits)
Ideal line
111
−
1
0
1
2
3
100
011
010
001
000
Zero-scale errors
