Electronic device and control method for the same

An electronic device comprises a first converter circuit converting an input voltage from a first or second power source to a first output voltage being 1/n of the input voltage (n>=2); a second converter circuit converting the input voltage from the second power source to a second output voltage; and a third converter circuit converting a higher one of the first and second output voltages to a third output voltage to be supplied to a load. The device, if the input voltage from the first power source is supplied to the first converter circuit, sets the second output voltage to be higher than a currently set voltage and lower than 1/n of the input voltage. The device then performs control to supply the input voltage from the first power source to the first converter circuit.