power nucleo 32 from lipo battery

DPiór.1 · ‎2025-03-28

Hi,

I have STM32 NUCLEO-L432KC Nucleo-32, I would like to power it from a li-pol battery. Is it possible?

Andrew Neil · ‎2025-03-28

@Peter BENSCH wrote:
the NUCLEO doesn't care what is connected to the power supply as long as it is within the appropriate range.

But the range specified in the UM seems a bit conservative ?

Where did the 4.75V minimum come from?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

DPiór.1 · ‎2025-03-29

One more question: does the SB9 need to be removed when connecting battery to +5V (and USB not connected)?

In manual, in the table it does not say that it needs to be removed.

However in other place of the manual it says that it must be removed.

Looking at the schematics, I think that when SB9 is ON and USB not connected, then reset will be permanently ON. But I'm not sure about that.

Peter BENSCH · ‎2025-04-08

If you want to supply the NUCLEO-L432KC exclusively via +5V (CN4.4), the embedded ST-LINK receives no supply voltage due to D3 and D4, so that its output PB0 (T_NRST) is undefined and is usually read as low. For this reason, the second sentence you framed recommends removing SB9 so as not to block the target.

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