Hello, can anybody tell me the maximum allowed voltage flowing into STM32 when in Open-Drain-mode on an STM32G030F6? The datasheet does not show any overvoltage protection diodes, so I am wondering if it is possible to sink 12V limited to 50µA?

[ulri]

The concrete use case is that I want to control a p-channel-MOSFET which gate is pulled up to 12V via an external 10kOhm resistor.

To switch the MOSFET I have to pull the gate down to GND, so I thought about using Open-Drain-output mode to let the 12V (limited by the external 10kOhm resistor) flow to ground.

Are there any protection diodes which would conduct from this 12V GPIO to e.g. VDD to limit input voltage?

Kind regards

Robin

[waclawek.jan]

> I am wondering if it is possible to sink 12V limited to 50µA?

No.

> Are there any protection diodes which would conduct from this 12V GPIO to e.g. VDD to limit input voltage?

In TC pins and pins set to Analog, yes.

In FT pins, it's not exactly a diode, but a protection structure, which may get damaged or cause malfunction, if the VDD + 4.0V condition is violated.

Generally, see Absolute maximum ratings in Datasheet.

JW

[S.Ma]

You can dig on semiconductor process oxide layer breakdown voltage to know more about physical limits, followed by design limits.

[waclawek.jan]

Generally, yes.

The trouble here is, that you have no data, except if you are an ST engineer - but in that case you wouldn't ask in a user forum - or at least I hope so :)

This is why you generally to stick to the datasheet information. You can, of course, go down the slippery path of "oh I've tried and it's perfectly fine, it works for me", but I personally try to avoid it.

JW