Datasheet

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STM32F37xxx Electrical characteristics
114
Equation 1: R
SRC
max formula
The formula above (Equation 1) is used to determine the maximum external signal source
impedance allowed for an error below 1/4 of LSB. Here N = 12 (from 12-bit resolution).
Table 61. R
SRC
max for f
ADC
= 14 MHz
(1)
1. Guaranteed by design, not tested in production.
T
s
(cycles) t
S
(µs) R
SRC
max (kΩ)
1.5 0.11 0.4
7.5 0.54 5.9
13.5 0.96 11.4
28.5 2.04 25.2
41.5 2.96 37.2
55.5 3.96 50
71.5 5.11 50
239.5 17.1 50
Table 62. ADC accuracy
(1)(2) (3)
1. ADC DC accuracy values are measured after internal calibration.
Symbol Parameter Test conditions Typ Max
(4)
Unit
ET Total unadjusted error
f
ADC
= 14 MHz, R
SRC
< 10 kΩ,
V
DDA
= 3 V to 3.6 V
T
A
= 25 °C
±1.3 ±3
LSB
EO Offset error ±1 ±2
EG Gain error ±0.5 ±1.5
ED Differential linearity error ±0.7 ±1
EL Integral linearity error ±0.8 ±1.5
ET Total unadjusted error
f
ADC
= 14 MHz, R
SRC
< 10 kΩ,
V
DDA
= 2.7 V to 3.6 V
T
A
= -40 to 105 °C
±3.3 ±4
LSB
EO Offset error ±1.9 ±2.8
EG Gain error ±2.8 ±3
ED Differential linearity error ±0.7 ±1.3
EL Integral linearity error ±1.2 ±1.7
ET Total unadjusted error
f
ADC
= 14 MHz, R
SRC
< 10 kΩ,
V
DDA
= 2.4 V to 3.6 V
T
A
= 25 °C
±3.3 ±4
LSB
EO Offset error ±1.9 ±2.8
EG Gain error ±2.8 ±3
ED Differential linearity error ±0.7 ±1.3
EL Integral linearity error ±1.2 ±1.7
R
SRC
T
S
f
ADC
C
ADC
2
N2+
()ln××
------------------------------------------------------------- - R
ADC
–<