IO pin current

NETMF & Gadgeteer
1

Hi

I see that the Cobra board has the EMX driving the Piezo directly from an IO pin (10).

What is the maximum current each IO pin can drive?

Investigating, I see the CPU datasheet (not the EMX one) states:

IOLS LOW-level short-circuit output current VOL = VDDA [10]- - 50 mA

So… can all pins drive up to 50mA, or am I way off here?

Typically I’d drive a transistor and have that switch an output but I’m wondering if this board has great drivers and I don’t need to…

Thanks!

2

The pins support 4 mA without stress. You can probably go above that for short spikes - as long as the total current through all pins doesn’t go over the total current allowed.
50 mA is a max. value for short-circuit: something you definitely don’t want to do.
The transistor will work fine. If you really need more current, a Darlington transistor will work fine.