Is it ok to keep unused pins of STM32G071C8T6 controller floating?

[VSira]

Hello,

In one of my application, I am using stm32g071c8t6 controller and 10-pins of controller are not utilized. I am having space constraint in PCB layout. Will it be fine if I keep all unused pins floating instead of pulling up/down using resistor?

[TDK]

Yes, it's perfectly fine, as long as the pins that matter (power, NRST, BOOT0, etc.) are correct.

[Amel NASRI]

Hi @VSira​ ,

The answer to your question is in AN5096: Getting started with STM32G0 Series hardware development. Here an extract:

-Amel

[gregstm]

If power consumption matters to you, make sure they are not floating inputs. Thankfully you don't need an external resistor to do this. Setting their mode as push-pull (low) is probably the most secure method (which will still allows you to use them as diagnostics later if needed - rather than physically connecting them to ground). I've had cases where using the weak internal pull-down (with input mode) still caused unexpected current consumption.