External Powering of Nucleo Boards

[corbinlamplot]

Hello, 

I am not experience enough in electronics to know if this is a dumb question but I'd like to know what the max current of the NUCLEO boards means. Is it the maximum current draw or the limit that is input from the output source? I'm wanting to power my board from a car charge port but most of the ports I find are 5V 2.4 amp and the board says the max current is 500mA. In the future if I decide to not power from USB and want to from the 3V3, that connection is attached to a current regulator that has a max current of 1.2A but on the max power setting the max current for the 3V3 is just '-'. Could I get some further explanation to how these things work? Thanks!

[TDK · Accepted solution]

Voltage is provided, current is taken.

That means the port you use (in this case 5 V 2.4 A) provides 5 V, and the load (nucleo board) pulls whatever current it needs from that, in this case probably somewhere around 100 mA. The "2.4 A" is a max available current, and the max 500 mA of the nucleo board is certainly less than that.

You can power it just fine from a 5V or 3.3V source that can provide at least 200mA or so, which is most of them.

[corbinlamplot]

Awesome, thank you!