3 A hold current, 6 V max — the PTC resettable fuse for tight board budgets
The Littelfuse 1206L300SLTHYR is a Polymeric PTC resettable fuse from the POLY-FUSE®, LoRho series.
Initial resistance and post-trip recovery — what the LoRho rating means for your rail
The LoRho designation signals a low-resistance PTC: initial resistance (Ri) is 3 mOhms minimum, and post-trip resistance (R1) maxes at 20 mOhms. After a fault clears and the PTC cools, the resistance settles back to the Ri range, so the circuit resumes normal operation without a manual reset. The 50 A maximum fault current rating means the PTC can interrupt a short-circuit current up to that level without rupturing. In a typical USB or battery-protection application where the upstream supply can source tens of amps, this rating ensures the fuse clears the fault before the trace or connector fails.
Package, approvals, and temperature range — board-fit checklist
Approved by cURus and TUV, the part carries the safety certifications required for equipment sold into North American and European markets.