Codesign of Electrostatic Discharge Protection Device and Common Mode Suppression Circuit on Printed Circuit Board

A codesign of an electrostatic discharge (ESD) protection device and a common-mode suppression circuit on printed circuit board (PCB) for high-speed input/output interfaces is introduced in this paper. The characteristic and the circuit model of the ESD protection device are investigated and applied into the design of the common-mode suppression circuit. The proposed one-stage design of two-layered PCB structure performs -10-dB common-mode noise suppression from 2.22 to 2.76 GHz; the proposed two-stage design with additional common-mode suppression unit performs wideband suppression from 2.25 GHz to over 8 GHz, covering IEEE 802.11ac WiFi band with -20-dB suppression level. The mode conversion for both designs is lower than -30 dB. The signal integrity and the ESD protection function of proposed design are investigated by eye diagram measurement and system-level ESD simulation. The proposed PCB design provides a low-cost solution for the integration on the high-speed input/output interface of next generation.