(A) high efficiency power conversion circuit with wide ZVS range for large screen PDP sustain power module

Abstract

Recently, due to the launch of digital broadcasting service, the demand of Flat Panel Display (FPD) is sharply rising. Among them, PDP is expected to be one of the most promising digital displays of next generation because of its large screen size, high resolution, thinness and board field of view. The PDP power module is mainly divided into Power Factor Correction (PFC) stage and Sustaining Power Stage. Especially, Sustaining Power Stage supplies power to PDP driver and various power stages so that the sustaining operation is mainly responsible for the overall system efficiency and size. Meanwhile, the PDP uses ADS (Address Display-period Separation) scheme which divide one subfield into address and sustaining period to express the gradation of images. For the output of sustaining power module is mostly used for sustaining period. Therefore, it is told that the sustaining power module``s load can be considered as a pulsating load. Due to this load condition, if the ZVS range of the power module is not guaranteed, the hard switching causes large amount of switching loss and serious thermal problem. In this paper, a high efficiency power conversion circuit for 60" PDP Sustain Power Module which achieves wide ZVS range with the help of additional ZVS tank is proposed. And the operations of the converter are analyzed applying various gate signals. To confirm the properties of the proposed converter, an experiment is completed using a high power prototype (about 900W). As the result, more than 92% of high efficiency is obtained at 10% load condition, and ZVS is achieved from full load to 10% load variation.