Switching mode power supply circuit for plasma display panel

PURPOSE: The present inventive concept relates to a switching mode power supply circuit for plasma display panel, and more particularly, to a switching mode power supply circuit for plasma display panel, in which a discharge resistor and a capacitor of an EMI filter unit are disposed following a relay unit, thereby reducing power consumption of the discharge resistor. CONSTITUTION: A switching mode power supply circuit for plasma display panel, comprising: an EMI filter unit; a PFC unit; an output unit; and a standby unit, wherein the EMI filter unit includes: a first line filter(111) connected to a commercial line input power; a first capacitor(C1) and discharge resistor connected to the first line filter; a second line filter connected to the first capacitor and discharge resistor; a second capacitor(C2) connected to the second line filter(113); and a relay unit disposed between the first line filter and the first capacitor and discharge resistor, the standby unit being connected to a contact point of the first line filter and the relay unit.