01-31-2018 05:34 AM
Hi,
I am attaching another custom made board on top of the 9683 RMC.
There, I need to feed some 3.3-Volt circuitry, which will demand about 24-30 mA.
I am tempted to draw that current from pins 1 and 3 of the 60-pin LVTTL connector... however, if these pins behave like the other pins, because the manuals say that only a 3-mAmp supply is guaranteed per pin, I would get just 6 mA.
So, how could I manage to get from 24 to 30 mA? Does it make sense to configure other DIO pins as outputs, and set them high, e.g. all eight DIO7:0 simultaneously, to source 24 mA?
Thank you!
Biscay.
Solved! Go to Solution.
01-31-2018 04:42 PM - edited 01-31-2018 04:46 PM
Pins 1 and 3 of the 60-pin LVTTL connector are not limited by the 3 mA spec of the signal pins. These +3.3V pins are connected to the FPGA_VIO rail on the sbRIO, which can supply up to .33 A.
Will
National Instruments
02-01-2018 11:06 AM
Will,
Thank you for your reply!
However, out of those 330mA that the FPGA_VIO rail can supply, how many are consumed on the RMC, and, then, how many are left for "other uses" such as mine?
Biscay.
02-01-2018 04:15 PM
The RMC itself will consume approximately ~71mA typical or ~228mA max from that rail. So you should be fine pulling an additional 30 mA.
02-01-2018 04:26 PM
Great! Thanks again. Biscay.
PS: I may have missed all that information in the manuals, but in case I didn't... I think it's a good idea to provide these figures in the datasheets etc.