# Absolute maximum ratings for STM32F103C8

#### kalemaxon89

Joined Oct 12, 2022
61
I need to use the stm32f103c8 and I am asking you to confirm whether I have read the following parameters correctly:

Maximum Sink and Source GPIOs Current:
"GPIOs (general-purpose inputs/outputs) can absorb or generate up to ±8 mA, and absorb or generate up to ±20 mA (with a relaxed VOL/VOH).
up to ±20 mA (with a relaxed VOL/VOH) with the exception of PC13, PC14 and PC15, which can
sink or source up to ±3 mA"

What does 'relaxed VOL/VOH' mean?
I have always known that stm32 often has a sink current of around 20 mA but would like confirmation/explanation from you.

Maximum GPIOs Input Voltage:
Input voltage on 5V tolerant pin --> Vdd+4.0V
Input voltage on any other pin --> 4.0V

Vdd:
I read Vdd = 2.0 to 3.6 V but in 'Table 6. Voltage characteristics' I read Vdd max = 4V.
How come?

Thanks to everyone

Last edited:

#### dl324

Joined Mar 30, 2015
15,423
What does 'relaxed VOL/VOH' mean?
I have always known that stm32 often has a sink current of around 20 mA but would like confirmation/explanation from you.
It means VOH will be lower than the datasheet indicates and VOL will be higher.

At first glance, it looks like sinking or sourcing 20mA would be safe (the absolute max is specified as 25mA; which the device isn't guaranteed to survive), but you should dig into the datasheet to find out if there are additional constraints for dissipation from the PORT that the I/O is a member of.
I read Vdd = 2.0 to 3.6 V but in 'Table 6. Voltage characteristics' I read Vdd max = 4V.
How come?
4V is the absolute maximum for Vdd. The device isn't guaranteed to survive being operated at that voltage.