The datasheet values for RAIN max are somewhat onerous, as I would need to buffer pretty much all my ADC inputs to support decently fast sampling. But they don't seem to fit with the equation suggested by the design guides. Is there something about the STM32G4 ADC that causes the need for higher sampling times? Here is an excerpt of the STM32G474 datasheet:
and an equation that doesn't fit the table regardless of the unspecified RADC value:
