A piezoelectric transformer based inverter topology for immerging CCFL inverter

In this paper, different CCFL (Cold Cathode Fluorescent Lamp) inverter topologies are discussed and analyzed and are compared to the piezoelectric transformer based topology. One of the main concerns is how to over come the negative resistance and parasitic capacitance effects in each topology. CCFL tubes and their construction are described to understand the tubes electrical characteristics. Due to its size, luminance, life and efficiency, CCFLs are the preferred source of illumination for larger LCD panels. There are different well established topologies of inverters that are used to drive the CCFL. These include the Royer self resonant oscillator, Push-Pull, and Full bridge inverter. The challenge in designing an inverter is to overcome the negative resistance characteristics of the tubes and to compensate for the parasitic capacitance. These issues are discussed in detail. A driver for the tube has been simulated and implemented in the lab. The design considers the negative resistance and parasitic capacitance issues.