Is it possible to power VIOLA carrier board with a voltage different than 5V?
According to the datasheet (Page 12), that is not possible. However, in the schematics, page NUMBER 3, that is possible if certain conditions to be followed.
Click in “Schematics and Datasheet” in order to download schematics and datasheet.
External power supply rated higher than 5V DC will result in permanent damaged of connected
Colibri module, connected devices and few components on the carrier board due to overvoltage.
If you require a higher voltage, you can use Iris carrier board, which supports 6-27V DC.
The Viola board has a 3.3V power supply which allows Vin (PWR_IN) in 4.7V-23V range. But that Vin also used to power Viola’s USB circuits. So it should be exactly 5V. If you don’t need a USB functionality you can remove R57 and double check that R2, R70 and R71 are not assembled. Then you can power Viola from a higher voltage. Please be aware that such a modification will void a warranty.