Timing skew enabler induced by fiber weave effect in high speed HDMI channel by angle routing technique in 3DFEM

Abstract

Fiber skew is one of the most difficult problems to debug. This paper investigates the timing skew problem on high speed, high-definition multimedia interface (HDMI) channel due to the fiber weave effect of Printed circuit board (PCB). This skew causes an asymmetry between the signals in the two lines and converts some of the differential signal into common signal, thereby, distorting the rise time of the differential signal, causing ISI, resulting in the collapse of the eye, and leading to deterministic jitter. In this paper, a method is proposed to minimize intra pair skew and jitter induced by the fiber weave effect. It is a geometry based method to understand the physical degradations in the PCB. The proposed method verified by using the 3DFEM technique in the differential line.