CORA Z8 Power supplies

[PW2]

How much current can I draw from the 3V3 supply on the headers?

[Bianca]

Hi @PW2

We didn't specify this in the Pmod Interface Specification but it shouldn't be more than 100mA. The 3V3 power supply is designed to provide 2A, however, it is used to power other ICs on the board, the FPGA bank and not only to be output in the Pmod or shield interface. 

Regards,

Bianca

 

[PW2]

Thanks for that remarkably swift response Bianca.

 

I feared that might be the case.  However I see that the 5 VDC from the power jack seems to connect directly to pin 5 of J8.  I presume that if I don’t exceed the rated current of that pin connector nor of the power jack and provide enough current to the power jack that I can regulate down the 5V5?

[JColvin]

Hi @PW2,

I'm not certain where you are getting the 5V5 (or if that was a typo), but the 2A from the 3.3V line that Bianca mentioned is from on-board regulator (IC15). You are correct in that the 5VDC from the power jack does connect directly to pin 5 of J8 (labeled as 5V0 on the silkscreen) when JP3 is set to EXT.

If your power supply has enough wattage, I suppose you could use an external regulator to step down that voltage to 3.3V to power other devices (presuming I am interpreting your question correctly), though this would be done at your own risk. I've seen more than one board get smoked out when messing with power settings.

Let us know if you have questions about this.

Thanks,
JColvin