Renesas rl78 User Manual

Page of 1004
 
RL78/G1A 
 
CHAPTER  11   A/D  CONVERTER 
R01UH0305EJ0200  Rev.2.00 
 
 
395  
Jul 04, 2013 
(5) Full-scale 
error 
This shows the difference between the actual measurement value of the analog input voltage and the theoretical 
value (Full-scale 
− 3/2LSB) when the digital output changes from 1......110 to 1......111.  
 
(6)  Integral linearity error 
This shows the degree to which the conversion characteristics deviate from the ideal linear relationship. It expresses 
the maximum value of the difference between the actual measurement value and the ideal straight line when the zero-
scale error and full-scale error are 0. 
 
(7)  Differential linearity error 
While the ideal width of code output is 1LSB, this indicates the difference between the actual measurement value and 
the ideal value. 
 
 
Figure 11-40.  Zero-Scale Error 
Figure 11-41.  Full-Scale Error  
 
 
111
011
010
001
Zero-scale error
Ideal line
000
0
1
2
3
AV
REF
Digital output (Lo
w
er 3 bits)
Analog input (LSB)
 
111
110
101
000
0
AV
REF
−3
Full-scale error
Ideal line
Analog input (LSB)
Digital output (Lo
w
er 3 bits)
AV
REF
−2 AV
REF
−1 AV
REF
 
 
 
Figure 11-42.  Integral Linearity Error 
Figure 11-43.  Differential Linearity Error 
 
 
0
AV
REF
Digital output
Analog input
Integral linearity
error
Ideal line
1......1
0......0
 
0
AV
REF
Digital output
Analog input
Differential 
linearity error
1......1
0......0
Ideal 1LSB width
 
 
(8) Conversion 
time 
This expresses the time from the start of sampling to when the digital output is obtained. 
The sampling time is included in the conversion time in the characteristics table. 
 
(9) Sampling 
time 
This is the time the analog switch is turned on for the analog voltage to be sampled by the sample & hold circuit. 
 
Sampling
time
Conversion time