Document Number: 002-04713 Rev.*A
Page 52 of 65
MB96640 Series
14.5.3 Definition of A/D Converter Terms
• Resolution
: Analog variation that is recognized by an A/D converter.
• Nonlinearity error
: Deviation of the actual conversion characteristics from a straight line that connects the zero
transition point (0b0000000000 ←→ 0b0000000001) to the full-scale transition point
(0b1111111110 ←→ 0b1111111111).
• Differential nonlinearity error: Deviation from the ideal value of the input voltage that is required to change the
output code by 1LSB.
• Total error
: Difference between the actual value and the theoretical value. The total error includes zero
transition error, full-scale transition error and nonlinearity error.
• Zero transition voltage : Input voltage which results in the minimum conversion value.
• Full scale transition voltage: Input voltage which results in the maximum conversion value.
Nonlinearity error of digital output N =
V
NT
- {1LSB
(N - 1) + V
OT
}
[LSB]
1LSB
Differential nonlinearity error of digital output N =
V
(N + 1) T
- V
NT
- 1 [LSB]
1LSB
1LSB =
V
FST
- V
OT
1022
N
: A/D converter digital output value.
V
OT
: Voltage at which the digital output changes from 0x000 to 0x001.
V
FST
: Voltage at which the digital output changes from 0x3FE to 0x3FF.
V
NT
:
Voltage at which the digital output changes from 0x(N − 1) to 0xN.