How to Perform EMC Design for High-Speed Data Interfaces such as USB and Ethernet Ports in Limited Space?

The design must balance signal integrity and anti-interference capability. For interfaces like USB 2.0 or Ethernet, the focus of protection lies in suppressing common-mode noise and dissipating ESD energy. It is recommended to use ultra-low capacitance multi-channel ESD protection arrays, with a single-line capacitance typically below 0.5 pF, to provide an electrostatic discharge path to ground for data lines without affecting signal rise time. Additionally, placing common-mode chokes in series on the data lines can effectively filter out common-mode interference introduced by cables. During layout and routing, both ESD protection devices and common-mode chokes should be placed close to the connector, ensuring continuous signal trace impedance and minimizing the ground loop area. This approach achieves effective protection in limited space without compromising eye diagram quality.