
Edge computing boxes with hot-swappable USB 2.0/3.0 interfaces and high ESD risks require the selection of low-capacitance ESD protection devices to prevent signal attenuation. For USB 2.0, the recommended ESD protection device is ESDLC5V0D8B (named ESD electrostatic LC low capacitance 5V0, shutdown voltage 5.0V, D8, SOD882 package, DFN1006-2L). Its typical junction capacitance is 5pF, capable of withstanding ±30kV contact discharge without interrupting 480Mbps signals. For USB 3.0 speeds of 5Gbps, even smaller capacitance is required; ESDLC5V0D8B is recommended. Its ULC ultra-low capacitance is <0.5pF, D8 package, supporting 5Gbps differential signals. It is also recommended to connect a self-resetting fuse SMD2920-050-60V (named SMD2920, 050 package, holding current 0.5A, 60V withstand voltage) in series with the VBUS power line to prevent short-circuit damage and to add a common-mode filter CMZ2012A-900T (named CM common-mode Z impedance 2012, size 2.0×1.2mm). With a 900T impedance of 90Ω and 100MHz suppression of high-frequency common-mode radiation, the USB interface of this selected edge box passed ESD 8kV contact and EFT 2kV tests without any degradation in communication speed.