MB90340E Datasheet, PDF (66/84 Pages) Fujitsu Component Limited. – 16-bit Microcontroller

MB90340E Series
6. Definition of A/D Converter Terms
Resolution : Analog variation that is recognized by the A/D converter.
Non linearity : The deviation between the actual conversion characteristics and a line that joins the
error
zero-transition line ( “00 0000 0000” ← → “00 0000 0001” ) to the full-scale transition line
( “11 1111 1110” ← → “11 1111 1111” ) .
Differential : Deviation of input voltage, which is required for changing output code by 1 LSB, from an
linearity error ideal value.
Total error
: Difference between the actual value and the ideal value. The total error includes zero
transition error, full-scale transition error, and linear error.
3FFH
3FEH
3FDH
Total error
Actual conversion
characteristics
1.5 LSB
{1 LSB × (N − 1) + 0.5 LSB}
004H
003H
002H
001H
AVRL
VNT
(Actually-measured value)
Actual conversion
characteristics
Ideal characteristics
0.5 LSB
Analog input
AVRH
VNT − {1 LSB × (N − 1) + 0.5 LSB}
Total error of digital output “N” =
1 LSB
1 LSB (Ideal value) = ^{AVRH − AVRL} [V]
1024
[LSB]
N : Value of the digital output from the A/D converter
VOT (Ideal value) = AVRL + 0.5 LSB [V]
VFST (Ideal value) = AVRH − 1.5 LSB [V]
VNT : A voltage at which the digital output transitions from (N − 1)H to NH.
(Continued)
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