S124 Datasheet, PDF (77/98 Pages) Renesas Technology Corp – 32-bit ARM Cortex-M0+ microcontroller

S124
2. Electrical Characteristics
FFFh
Full-scale error
A/D converter
output code
Integral nonlinearity
error (INL)
Actual A/D conversion
characteristic
Ideal line of actual A/D
conversion characteristic
Ideal A/D conversion
characteristic
Differential nonlinearity error (DNL)
1-LSB width for ideal A/D
conversion characteristic
Differential nonlinearity error (DNL)
1-LSB width for ideal A/D
conversion characteristic
Absolute accuracy
000h
0
Offset error
Analog input voltage
VREFH0
(full-scale)
Figure 2.55 Illustration of 14-bit A/D converter characteristic terms
Absolute accuracy
Absolute accuracy is the difference between output code based on the theoretical A/D conversion characteristics, and the
actual A/D conversion result. When measuring absolute accuracy, the voltage at the midpoint of the width of the analog
input voltage (1-LSB width), which can meet the expectation of outputting an equal code based on the theoretical A/D
conversion characteristics, is used as the analog input voltage. For example, if 12-bit resolution is used and the reference
voltage VREFH0 = 3.072 V, then 1-LSB width becomes 0.75 mV, and 0 mV, 0.75 mV, and 1.5 mV are used as the analog
input voltages. If analog input voltage is 6 mV, an absolute accuracy of ±5 LSB means that the actual A/D conversion
result is in the range of 003h to 00Dh, though an output code of 008h can be expected from the theoretical A/D
conversion characteristics.
Integral nonlinearity error (INL)
Integral nonlinearity error is the maximum deviation between the ideal line when the measured offset and full-scale
errors are zeroed, and the actual output code.
Differential nonlinearity error (DNL)
Differential nonlinearity error is the difference between 1-LSB width based on the ideal A/D conversion characteristics
and the width of the actual output code.
Offset error
Offset error is the difference between the transition point of the ideal first output code and the actual first output code.
Full-scale error
Full-scale error is the difference between the transition point of the ideal last output code and the actual last output code.
R01DS0264EU0100 Rev.1.00
Feb 23, 2016
Page 77 of 95