What are the selection requirements for power supply fuses for optical modules in data center switches?

Data center switch optical modules are mostly powered by 3.3V/0.3-0.5A. Fuse selection must balance overcurrent protection and low voltage drop. The Yinte Electronics SMD0603-050-6V (holding current 0.5A, withstand voltage 6V, initial resistance 0.15Ω, voltage drop <75mV@0.5A) is suitable for SFP/SFP+ scenarios with power consumption of 1-1.5W. The QSFP28 100G optical module, with power consumption of 3.5W/3.3V, requires 1.1A current; the SMD1812-110-6V (holding current 1.1A) should be selected. Selection must also meet surge withstand requirements; the peak inrush current during hot-swapping of the optical module must be 2-3 times the steady-state current, requiring a PTC action time >10ms to prevent false triggering. Simultaneously, a parallel TVS such as ESD3V3D3B (VRWM=3.3V, junction capacitance 12pF) should be used to protect against ESD. Actual testing showed no PTC malfunction and a power drop of <2% after 1000 hot-swapping cycles.