Datasheet

Electrical characteristics
STM8S105xx
It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may potentially inject
negative current. Any positive injection current within the limits specified for I
INJ(PIN)
and ΣI
INJ(PIN)
in the I/O port
pin characteristics section does not affect the ADC accuracy.
Table 47: ADC accuracy with RAIN < 10 kΩ RAIN, VDDA = 3.3 V
Symbol Parameter Conditions Typ Max
(1)
Unit
|E
T
| Total unadjusted error
(2)
f
ADC
= 2 MHz 1.1 2.0 LSB
f
ADC
= 4 MHz 1.6 2.5
|E
O
| Offset error
(2)
f
ADC
= 2 MHz 0.7 1.5
f
ADC
= 4 MHz 1.3 2.0
|E
G
| Gain error
(2)
f
ADC
= 2 MHz 0.2 1.5
f
ADC
= 4 MHz 0.5 2.0
|E
D
| Differential linearity error
(2)
f
ADC
= 2 MHz 0.7 1.0
f
ADC
= 4 MHz 0.7 1.0
|E
L
| Integral linearity error
(2)
f
ADC
= 2 MHz 0.6 1.5
f
ADC
= 4 MHz 0.6 1.5
Notes:
(1)
Data based on characterization results, not tested in production.
(2)
ADC accuracy vs. negative injection current: Injecting negative current on any of the analog input pins should
be avoided as this significantly reduces the accuracy of the conversion being performed on another analog input.
It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may potentially inject
negative current. Any positive injection current within the limits specified for I
INJ(PIN)
and ΣI
INJ(PIN)
in Section
13.3.6: "I/O port pin characteristics"
does not affect the ADC accuracy.
Figure 45: ADC accuracy characteristics
1. Example of an actual transfer curve.
2. The ideal transfer curve
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