2021-09-07 06:42 PM
2021-09-07 11:01 PM
Unless I'm wrong, ADC will work properly within gnd and vdda. Vdda is vdd when not exposed in the selected package. Going more than the operating range will accelerate wear and tear of the chip. At AMR absolute max rating, the chip may last 1000h. Over this will be non guaranteed and destructive. The pin properties depends on its physical properties, not by its selected function.
2021-09-08 07:00 AM
On the F4, most pins were tolerant, but only in input mode and there is a note in the datasheet to indicate this.
5. FT = 5 V tolerant except when in analog mode or oscillator mode (for PC14, PC15, PH0 and PH1).
On the L0, this note is removed. That would lead me to believe they are 5V tolerant in analog mode. However, I can't see that explicitly stated anywhere.
The H7 has some pins which are analog-only (e.g. PA0_C). These are listed as TT type (3.3V tolerant I/O). This would lead me to believe that analog pins are not 5V tolerant.
So who knows. Can't see anything definitive online.
2021-09-08 11:08 PM
Yeah agreed, managed to track this down though app note AN4899 which states on page 18:
"A GPIO is five-volt tolerant only if there is no analog function enabled on pin (for I/O structure FT_a, FT_fa, TT_a). If some analog input function is enabled on the GPIO (ADC input active, COMP input, OPAMP input), then the maximum operating voltage on pin cannot exceed min(VDDA, VREF+) + 0.3 V."
so guess that must be across all MCU's and they chose to leave out of some datasheets