A new sustain driver employing a step-tip function is presented to achieve the faster rise-time of sustain voltage, which is suitable for widely used address-and-display-period-separated (ADS) driving method, and most of all for cost saving. The proposed sustain driver can reduce the number of switching devices by 25 (%) compared to the prior approach improving the overall system efficiency about 10 (%). And brightness decrease problem resulted from the lack of the number of the sustain pulse can be solved without a limitation to sustain pulse width. Operational principle and its features are illustrated comparing with conventional approaches. The validity of the proposed sustain driver is verified through experiments using a prototype equipped with a 7.5 (inch) diagonal panel, which is operated at 200 (kHz) switching frequency.(1).