r5s72060w200fpv Renesas Electronics Corporation., r5s72060w200fpv Datasheet - Page 873

• Manufacturer Part Number: r5s72060w200fpv
• Description: 32-bit Risc Microcomputer Superhtm Risc Engine Family / Sh7200 Series
• Manufacturer: Renesas Electronics Corporation.

17.6
The A/D converter compares an analog value input from an analog input channel with its analog
reference value and converts it to 10-bit digital data. The absolute accuracy of this A/D conversion
is the deviation between the input analog value and the output digital value. It includes the
following errors:
• Offset error
• Full-scale error
• Quantization error
• Nonlinearity error
These four error quantities are explained below with reference to figure 17.7. In the figure, the 10
bits of the A/D converter have been simplified to 3 bits. Offset error is the deviation between
actual and ideal A/D conversion characteristics when the digital output value changes from the
minimum (zero voltage) B'0000000000 (000 in the figure) to B'000000001 (001 in the
figure)(figure 17.7, item (1)). Full-scale error is the deviation between actual and ideal A/D
conversion characteristics when the digital output value changes from B'1111111110 (110 in the
figure) to the maximum B'1111111111 (111 in the figure)(figure 17.7, item (2)). Quantization
error is the intrinsic error of the A/D converter and is expressed as 1/2 LSB (figure 17.7, item (3)).
Nonlinearity error is the deviation between actual and ideal A/D conversion characteristics
between zero voltage and full-scale voltage (figure 17.7, item (4)). Note that it does not include
offset, full-scale, or quantization error.
Digital output
111
110
101
100
011
010
001
000
[Legend]
FS: Full-scale voltage
0
Definitions of A/D Conversion Accuracy
1024
1
1024
2
characteristic
Figure 17.7 Definitions of A/D Conversion Accuracy
conversion
Ideal A/D
(3) Quantization
error
1022
1024
1023
1024
Analog input
voltage
FS
Digital output
characteristic
Rev. 2.00 Dec. 09, 2005 Page 849 of 1152
conversion
(1) Offset error
Ideal A/D
Actual A/D
convertion
characteristic
Section 17 A/D Converter (ADC)
(4) Nonlinearity
(2) Full-scale error
error
REJ09B0191-0200
Analog input
voltage
FS