AN2615 Datasheet, PDF (25/37 Pages) STMicroelectronics – In general the ADC embedded in the ST7 microcontroller

AN2615
Result
Table 2. Results for negative input voltages (continued)
Sl
no
V_in (mV)
(taken from multimeter)
V_measured (mV)
Difference (mV)
(V_measured - V_in)
Error in max and min input
measured in the loop (mV)
33
-778.54
-780.59
-2.05
0.37
34
-818.25
-820.42
-2.17
0.43
35
-858.27
-860.61
-2.34
0.56
36
-898.57
-901.07
-2.5
0.2
37
-938.31
-940.94
-2.63
0.67
38
-978.21
-981.03
-2.82
0.43
Figure 17 shows the relationship between measured voltages V_measured (average of the 16
readings measured by the converter) and input voltage V_in (as measured by the multimeter)
for negative voltages.
Figure 17. Measured vs input for negative voltages
Figure 18. Error vs input for negative input voltages
Figure 18, shows that for negative input voltages varying from 0 to -1 V, the maximum error
is around -2.89 mV for -1 V input. An error of 0.5 mV occurs for an input value of -269 mV
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