A power supply of a plasma display device includes a power source unit configured to convert a direct current source into an alternating current source, a transformer including a primary side winding electrically coupled to the power source unit and a secondary side winding having a first winding and a second winding, a sustain power supply electrically coupled to the first winding of the secondary side of the transformer, the sustain power supply configured to output a first voltage to a first voltage output terminal, and an address power supply electrically coupled to the second winding of the secondary side and serially connected to the sustain power supply, the address power supply configured to output a second voltage to a second voltage output terminal.