LoRho series — low-resistance PTC for tight voltage budgets
The 1206L500SLWR: This is a polymeric PTC resettable fuse from Littelfuse's POLY-FUSE LoRho family, engineered for applications where every milliohm of series resistance matters. The initial resistance is 100 mOhms minimum, and the post-trip resistance holds at 12 mOhms maximum — an order of magnitude lower than standard PTCs, which keeps voltage drop across the fuse negligible in a 6 V rail. Rated for 5 A hold current (Ih) with a 10 A trip current (It), it handles normal operation up to 5 A and trips within 2 seconds at fault current levels. The maximum fault current it can interrupt is 50 A at 6 V, giving it solid short-circuit capability for low-voltage power distribution.
1206 footprint — standard pick-and-place fit
Surface-mount construction means it flows through reflow soldering alongside other passives — no manual assembly step.