CD00191174 Datasheet, PDF (94/112 Pages) STMicroelectronics – High-density access line, ARM-based 32-bit MCU

Electrical characteristics
STM32F101xC, STM32F101xD, STM32F101xE
The formula above (Equation 1) is used to determine the maximum external impedance
allowed for an error below 1/4 of LSB. Here N = 12 (from 12-bit resolution).
Table 56. R_AIN max for f_ADC = 14 MHz⁽¹⁾
T_s (cycles)
t_S (µs)
1.5
0.11
7.5
0.54
13.5
0.96
28.5
2.04
41.5
2.96
55.5
3.96
71.5
5.11
239.5
17.1
1. Guaranteed by design, not tested in production.
0.4
5.9
11.4
25.2
37.2
50
NA
NA
R_AIN max (kΩ)
Table 57.
Symbol
ADC accuracy - limited test conditions⁽¹⁾⁽²⁾
Parameter
Test conditions
Typ Max⁽³⁾ Unit
ET Total unadjusted error
EO Offset error
EG Gain error
ED Differential linearity error
EL Integral linearity error
f_PCLK2 = 28 MHz,
f_ADC = 14 MHz, R_AIN < 10 kΩ,
V_DDA = 3 V to 3.6 V, T_A = 25 °C
Measurements made after
ADC calibration
V_REF+ = V_DDA
±1.3
±1
±0.5
±0.7
±0.8
±2
±1.5
±1.5 LSB
±1
±1.5
1. ADC DC accuracy values are measured after internal calibration.
2. 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 I_INJ(PIN) and ΣI_INJ(PIN) in Section 5.3.13 does not
affect the ADC accuracy.
3. Based on characterisation, not tested in production.
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Doc ID 14610 Rev 8