Hardware manual

53
FUJITSU SEMICONDUCTOR CONFIDENTIAL
MB96630 Series
DS704-00012-1v0-E
(3) Definition of A/D Converter Term s
• 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
Differential nonlinearity error
Digital output
Digital output
Actual conversion
characteristics
Actual conversion
characteristics
Ideal characteristics
Actual conversion
characteristics
Actual conversion characteristics
Ideal characteristics
Analog input
Analog input
0x001
0x002
0x003
0x004
0x3FD
0x3FE
0x3FF
AV
SS
AVRH AV
SS
AVRH
0x(N-2)
0x(N-1)
0x(N+1)
0xN
{1 LSB(N-1) + V
OT
}
V
NT
(Actually-measured
value)
V
FST
(Actually-
measured
value)
V
OT
(Actually-measured value)
V
NT
(Actually-measured
value)
V
(N+1)T
(Actually-measured
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.