Design and analysis of an SLPT-based CCFL driver

In this paper, a single-layer piezoelectric-transformer (SLPT)-based driver is realized for driving a cold-cathode fluorescent lamp (CCFL). First, a half-bridge resonant inverter is adopted for driving the SLPT and the CCFL to achieve zero-voltage-switching (ZVS) effect. In addition, a PQ-plane-design-oriented approach is presented for determining the power circuit parameters. Second, a feedback controller is proposed to match the power circuit control requirement. The feedback controller provides the proper switching frequency for the drive to be operated at the most efficient frequency. In addition, functions of dimming control and no-load protection are also available from the controller. Third, a small-signal model is derived and the closed-loop stability analysis is made to guarantee the stable tracking of the command signal of the controller. Finally, a hardware prototype is also constructed to verify the effectiveness of the proposed driver.