Polymeric PTC for tight board spots
The Littelfuse 1206L110/12SLYR is a Polymeric PTC resettable fuse from the POLY-FUSE® LoRho series, designed to protect circuits by tripping when current exceeds 2.2 A (It) and resetting once the fault clears. With a 1.1 A hold current (Ih) at 12 V max, it sits in the 1206 (3216 Metric) concave package — a common footprint for overcurrent protection on dense PCBs where board space is tight.
Trip response and resistance profile
This PTC trips in 300 ms (typical) at the rated current, fast enough to protect downstream components from sustained overcurrent without nuisance tripping on brief inrush. The initial resistance (Ri) is a minimum of 15 mOhms, keeping I²R losses low during normal operation; after tripping, the post-trip resistance (R1) rises to a maximum of 130 mOhms, holding the fault current in check until power is cycled. Rated for a maximum fault current of 50 A at 12 V, it handles short-circuit events up to that level without rupturing.
Compliance and sourcing posture
No direct pin-compatible second source is listed from the manufacturer, but the POLY-FUSE LoRho family includes other hold-current ratings in the same 1206 footprint if the 1.1 A value needs adjustment.