A-D CONVERTER
12.4 Absolute accuracy and Differential non-linearity error
12.4.2 Differential non-linearity error
The differential non-linearity error indicates the difference between the 1 LSB step width (the ideal analog
input voltage width while the same output code is expected to output) of an A-D converter with ideal
characteristics and the actual measured step width (the actual analog input voltage width while the same
output code is output). (See Figure 12.4.2 for more details.) For example, in the case of the 10-bit
resolution mode and VREF = 5.12 V, the 1 LSB width of an A-D converter with ideal characteristics is 5 mV;
but if the differential non-linearity error is ±1 LSB, the actual measured 1 LSB width is in the range from
0 to 10 mV.
Output code
(A-D conversion result)
00916
1 LSB width with ideal
A-D conversion characteristics
00816
00716
00616
00516
00416
00316
00216
00116
Differential non-linearity error
00016
0
5
10
15
20
25
30
35
40
45
Analog input voltage (mV)
Fig. 12.4.2 Differential non-linearity error (10-bit resolution mode)
7905 Group User’s Manual Rev.1.0
12-20
RENESAS [ RENESAS TECHNOLOGY CORP ]
