This Power bridge board is required because when the computing load of XU4 board get heavy, there is 0.5~0.6 ripple on 5V rail on the USB host port. The Ripple Volotage causes the flickering of the VU7 and/or VU7+LCD Backlight.
To avoid above mentiond issue can be resolved by using this power bridge board as a workaround.
You need to purchase 5V/2A PSU separately
Note: Power adapter is not included.