Low Rho SMD PPTCs Littelfuse Low Rho SMD PPTCs provide ultra-low normal operating resistance at normal operating hold current. Featuring a compact design, these fuses offer fast response times to fault currents with a maximum fault current rating of 40A. Littelfuse Low Rho SMD PPTCs are compatible with high-temperature solders and are available in a range of hold current ratings. These TUV- and UL-certified fuses are well-suited for USB peripherals including USB 3.0/2.0 ports, Li-ion/Li-Polymer battery packs, smartphones, tablet/notebook PCs, e-readers, LCD/LED HDTV, hard disk drives, digital/video cameras, computer peripherals, and game consoles.