STM32F103xC, STM32F103xD, STM32F103xE
Electrical characteristics
(1) (2)(3)
Table 62. ADC accuracy
Symbol
Parameter
Test conditions
Typ
Max(4)
Unit
ET
EO
EG
ED
EL
Total unadjusted error
Offset error
2
5
2.5
3
fPCLK2 = 56 MHz,
fADC = 14 MHz, RAIN < 10 kΩ,
VDDA = 2.4 V to 3.6 V
1.5
1.5
1
Gain error
LSB
Measurements made after
ADC calibration
Differential linearity error
Integral linearity error
2
1.5
3
1. ADC DC accuracy values are measured after internal calibration.
2. Better performance could be achieved in restricted VDD, frequency, VREF and temperature ranges.
3. ADC Accuracy vs. Negative Injection Current: Injecting negative current on any of the standard (non-
robust) 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 IINJ(PIN) and ΣIINJ(PIN) in Section 5.3.14 does not
affect the ADC accuracy.
4. Based on characterisation, not tested in production.
Figure 57. ADC accuracy characteristics
VREF+
VDDA
4096
[1LSBIDEAL
=
(or
depending on package)]
4096
E
G
(1) Example of an actual transfer curve
(2) The ideal transfer curve
4095
4094
4093
(3) End point correlation line
(2)
E =Total Unadjusted Error: maximum deviation
T
E
between the actual and the ideal transfer curves.
T
(3)
7
6
5
4
3
2
1
E =Offset Error: deviation between the first actual
O
(1)
transition and the first ideal one.
E =Gain Error: deviation between the last ideal
G
transition and the last actual one.
E
O
E
L
E =Differential Linearity Error: maximum deviation
D
between actual steps and the ideal one.
E =Integral Linearity Error: maximum deviation
L
E
between any actual transition and the end point
correlation line.
D
1 LSB
IDEAL
0
1
2
3
4
5
6
7
4093 4094 4095 4096
V
V
DDA
SSA
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Doc ID 14611 Rev 8
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STMICROELECTRONICS [ ST ]
