How protect GPIOs from ISO7637-3 Pulses?

[TLich.1]

Hi,

I would like to protect my GPIOs from ISO7637-3 pulses with a rail to rail diode solution. But I have seen that the GPIOs already have a intern rail to rail protection with a forward voltage Vf_int = 0.6V (Datasheet Fig. 43). To protect my GPIOs with a extern circuitry the Vf_ext has to be lower than Vf_int, is that right?

Kind regards

Tom

[Cristian Gyorgy]

Normally it's only around 0.3 V the forward voltage drop on the port reverse diodes. What datasheet do you have with 0.6 V?

[TLich.1]

I got the Information from this data sheet (p.85 fig.43): https://www.st.com/resource/en/datasheet/stm8af52a8.pdf

Where can I find the information of a forward voltage of 0.3V?