SI Considerations in Flexible Channels on High-Speed Intra-Panel Interface for Large-Size Flat Panel Display Applications

Abstract

In flat panel display modules with a large-size and high-resolution for TV applications, signaling channels are relatively short on flexible printed circuit (FPC) cable or chip-on-film (COF) package when compared to those of the source PCBs. However, the short distance channels can significantly affect overall signal integrity (SI) performance. Thus, this letter focuses mainly on analysis and design of signal interconnection on FPC cable and COF package in terms of impedance matching and crosstalk. By optimizing the FPC cable design to mitigate crosstalk as well as insertion loss, the opening area of eye diagram was found to be improved more than twice over the previous one. In addition, through adjusting process of on-die capacitance of electro-static discharge (ESD) protection circuitry in the input stage of a high-speed circuit block, the created parasitic inductance of COF package trace was observed to be compensated. This optimization process can improve greatly system performance by widening the input eye opening. Finally, we propose channel design considerations and design guidelines to ensure better SI performance in flexible channels on high-speed intra-panel interface for large-size liquid crystal display (LCD) TV applications.