Design Methodology for Transmission-Line Based (TMLB) Pi-Type ESD Protection Circuit

摘要

A matching theorem for the transmission-line based (TMLB) pi-type ESD circuit is found. To return the origin, the total degrees rotated by the matching circuit at the matching frequency is equal to pi or several times greater than pi. Based on this theorem and Smith chart, a methodology to design the TMLB pi-type ESD circuit as the narrowband matching circuit is presented. From the matching theorem or return loss prospect, the distributed ESD circuit is equivalent to three-stage TML pi-type ESD circuit, and therefore, it is a narrowband matching circuit, not a wideband matching circuit.