Powering Zybo-Z7-20 directly from USB charger???

[john_joe]

Hello everyone, 

that question may sound stupid, but is that possible to power up the Zybo-Z7 directly from the USB charger?

The reason for that is that I want to boot the board uinsg SD Card and use some peripherals including HDMI-in and HDMI-out and the current from the usb port is not enough.

Will charging the usb port directly to one charger such as the one from mobile phones damage the board?

I do apologise if that question is obvious or stupid and I appreciate any reply.

Thank you

[xc6lx45]

one unintended consequence is that it will put your board at a potential of 115 V RMS relative to ground (the typical charger has only two mains terminals without ground, and uses internally a high-impedance voltage divider to prevent a charge buildup between primary and secondary side). You can show it with a digital multimeter, on many units you can even feel the buzz when touching the low-voltage wire. Obviously, not all chargers are the same, on some you can't feel it and on others it's fairly unpleasant). That said, it's done frequently e.g. with Raspberry Pi. I can't comment on Zybo but I've used chargers to run FPGA boards standalone without incident.

[john_joe]

Thank you. Indeed I used it with a raspberry pi without problem with a charger outputting 5V and 1A. I was a bit reluctant to connect the Zybo, as it is way more expensive than a raspberry pi zero.

[JColvin]

Hi @john_joe

In principle it should be fine (provided the phone charger and the accepted input voltages by the board match); the main unknown factor as @xc6lx45 is the quality of the charger itself, does it actually provide the voltage it states, or does it have some voltage spikes? In theory ones provided with a new phone should be okay since you would hear a lot of complaints if the chargers provided fried the new phone upon connecting.

Thanks,
JColvin

[john_joe]

Thank you @JColvin. I tested it and is working fine.