Patent ID: 7978155

Claim:
A plasma display device having a plurality of first electrodes and a plurality of second electrodes for performing a display operation together with the plurality of first electrodes, the plurality of first electrodes and the plurality of second electrodes corresponding to a plurality of discharge cells defined in the plasma display device, the device comprising: a scan drive unit comprising a plurality of selection circuits each having a first switch and a second switch, the selection circuits being adapted to sequentially apply a scan voltage to some of the plurality of first electrodes through the first switches, and to apply a non-scan voltage to others of the plurality of first electrodes through the second switches; a sustain drive unit for applying a sustain pulse alternately having a first voltage and a second voltage lower than the first voltage to the plurality of first electrodes through the plurality of selection circuits; and a clamping unit coupled to at least one of the plurality of selection circuits and for clamping a voltage of a corresponding one of the plurality of first electrodes at the first voltage when the voltage of the corresponding one of the plurality of first electrodes exceeds the first voltage, wherein the clamping unit comprises a clamping diode having an anode directly coupled to an input terminal of the first switch and a cathode coupled to a first power supply for supplying the first voltage, such that the clamping diode is located between the input terminal and the first power supply, and the clamping unit further comprises a capacitor coupled at a connection point between the cathode of the clamping diode and the first power supply, wherein the capacitor is serially coupled to the diode between the input terminal of the first switch and a third voltage source.