Do the optical module interfaces of data center switches require ESD protection?

Although the optical module interface of the data center switch transmits signals via optical fiber, the electrical pins such as the I²C management bus, Tx_Disable, and Rx_LOS are exposed to electrostatic discharge (ESD) risks and must meet the IEC61000-4-2 ±8kV contact discharge requirements. The solution uses a YENTE Electronics NRESDTLC5V0D8B ultra-low residual voltage TVS (Vrwm=5V, junction capacitance 0.2pF, clamping voltage 9V) connected in parallel to the SFP cage pin. This device has a very small footprint due to its DFN1006 package. At the same time, it is used in conjunction with a PBZ1005B-501Z0T ferrite bead (47μH@100MHz, impedance 500Ω, DC resistance 0.25A) connected in series with the I²C clock and data lines to absorb high-frequency residual energy. The measured ESD ±8kV contact discharge resulted in a link reconnection time of <10ms without the optical module register flipping.