Zybo Xilinx Max Current , Wattage

[Team21]

Hello,

 

My team is trying to design a circuit with the Zybo board and we wished to power the circuit via an external battery and we were wondering what the maximum current & wattage allowance was. The datasheet specifies 5.5 Volts running through the board but nothing else. 

[zygot]

You ask a simple innocent question that has no simple answer. The answers is.. It depends... It depends on what external devices you are using (Ethernet?, the VGA driver?, the SD card?...For plain FPGA devices the main drivers for power requirements are how many IO are being driven?, what are the IO strandards and loads, what are the switching frequencies of the IO, followed by what are the internal clock frequencies? are you using all of the hard multipliers? and so on.. The Zybo has that nifty dual-core ARM processor hardware which is significant. Fortunatly, VIvado can help with an estimate of your power requirements... but only once you have a design for it to analyze.

 

One way to make an assessment of your needs might be to power up your ZYBO with, say both cores running Ubuntu ( assuming that you need to have all of those resources ) and measure the current draw on the power plug ( obviously, this requires a bit of DYI construction ) with a good current meter ( or possibly with a good magnetic current probe connected to an oscilloscope ( no DYI effort ). This might let you know if the ZYBO is a good platform or not for your needs. This is basic engineering practice. Sometimes the datasheets have the information that you need and sometimes they don't. And sometimes a simple experiement is better than hours of calculations.

[JColvin]

Hi Team21,

 

As zygot mentions, the current draw will be dependent on whatever peripherals you are running with the ZYBO board. As a reference though, in the ZYBO reference manual it recommends that if you are using a 5V "wall wart" power supply that it is able to provide at least 2.5A of current. You could use a more powerful 5V supply that allows for higher current draws if needbe. 

 

If you are concerned about running too much current/power through your ZYBO power rails to power all of your peripherals that you have going on without running into overheating issues, I would recommend trying to power any external applications with their own separate power supply. If everything you are doing is already built into the ZYBO board, then I believe a 5V 4A wall wart power supply will be plenty for your needs, but a 5V 2.5 power supply might also work. Again, it depends on how much current your design requires.

 

Let me know if you have any more questions.

 

Thanks,

JColvin