STM32F071C8T7 datasheet(85/121 Pages) STMICROELECTRONICS

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STM32F071CB STM32F071RB STM32F071VB STM32F071V8

Electrical characteristics

Figure 25. ADC accuracy characteristics

Figure 26. Typical connection diagram using the ADC

1. Refer to Table 56: ADC characteristics for the values of RAIN, RADC and CADC.

2. Cparasitic represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the

pad capacitance (roughly 7 pF). A high Cparasitic value will downgrade conversion accuracy. To remedy

this, fADC should be reduced.

General PCB design guidelines

Power supply decoupling should be performed as shown in Figure 12: Power supply

scheme. The 10 nF capacitor should be ceramic (good quality) and it should be placed as

close as possible to the chip.

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 IINJ(PIN) and ΣIINJ(PIN) in Section 6.3.14 does not affect the ADC

accuracy.

3. Better performance may be achieved in restricted VDDA, frequency and temperature ranges.

4. Data based on characterization results, not tested in production.

STM32F071C8T7 Datasheet(PDF) 85 Page - STMicroelectronics