2025-10-18 5:37 AM
I have made an adapter that sits between the STLink V3 and the device that needs to be programmed, so that I can give T_VCC on the STLink side 3.3V from an external supply.
So far I have used 3.3V as VCC on the target as well, but I am considering lowering VCC on target to 3.0V instead.
As far as I can tell from datasheets, there shouldn't be an issue with keeping T_VCC on the STLink side at 3.3V while VCC on target is 3.0V, but I wanted to check here if anyone has something different to say about this mismatch.
If it's a bad idea, I will need to have adapters around with T_VCC 3.0V and others with T_VCC 3.3V depending on which target device I work with, which in this case is a bit of a hassle.
2025-10-18 7:30 AM
That will case the ST-Link to send 3.3 V signals instead of 3.0 V, which is just on the threshold of okay, if internal pullups are used. If they are not used, there is even more margin.
So it'll be fine.