STM32F378RC datasheet(98/131 Pages) STMICROELECTRONICS

98 / 131 page

Electrical characteristics

STM32F378xx

98/131

DocID025608 Rev 4

Figure 28. ADC accuracy characteristics

Figure 29. Typical connection diagram using the ADC

1. Refer to Table 59 for the values of RSRC, 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 10. 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 a negative current on any 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 analog pins which may potentially inject

negative currents.

Any positive injection current within the limits specified for IINJ(PIN) and ΣIINJ(PIN) in Section 6.3.13 does not

affect the ADC accuracy.

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

4. Guaranteed by characterization results.

STM32F378RC Datasheet(PDF) 98 Page - STMicroelectronics