Powered from USB !, You can even power the entire display from a USB port. With the default 5" 800x480 display and 50mA backlight current, the current draw is 500mA total. You can reduce that down 370mA by running the backlight at half-brightness (25mA). With the backlight off, the decoder and display itself draws 250mA. If you want more backlight control, there's a PWM input, connect that to your microcontroller or other PWM output and you can continuously dim the backlight as desired.