SH7050 Datasheet, PDF (478/841 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperH RISC engine Family/

Section 14 A/D Converter
6. A/D conversion precision definitions
A/D conversion precision definitions are given below.
a. Resolution
The number of A/D converter digital conversion output codes
b. Offset error
The deviation of the analog input voltage value from the ideal A/D conversion
characteristic when the digital output changes from the minimum voltage value
0000000000 to 0000000001 (see figure 14.9).
c. Full-scale error
The deviation of the analog input voltage value from the ideal A/D conversion
characteristic when the digital output changes from 1111111110 to 111111111 (see figure
14.9).
d. Quantization error
The deviation inherent in the A/D converter, given by 1/2 LSB (see figure 14.8).
e. Nonlinearity error
The error with respect to the ideal A/D conversion characteristic between the zero voltage
and the full-scale voltage. Does not include the offset error, full-scale error, or quantization
error.
f. Absolute precision
The deviation between the digital value and the analog input value. Includes the offset
error, full-scale error, quantization error, and nonlinearity error.
Digital output
111
Ideal A/D conversion
110
characteristic
101
100
011
010
Quantization
001
error
000
Digital output
Full-scale error
Ideal A/D conversion
characteristic
Nonlinearity
error
Actual A/D conversion
characteristic
0 1/8 2/8 3/8 4/8 5/8 6/8 7/8 FS
Analog input voltage
Offset error
FS
Analog input voltage
Figure 14.9 A/D Conversion Precision Definitions
Rev. 5.00 Jan 06, 2006 page 458 of 818
REJ09B0273-0500