What this PTC fuse does on your board
The 0603L001/60YR is a Littelfuse POLY-FUSE® polymeric PTC resettable fuse — it protects low-current signal or power rails from overcurrent faults by switching from low-resistance to high-resistance when the trip current is exceeded, then resetting when power is removed and the device cools. Hold current is 10 mA max, trip current is 50 mA — the rail must stay below 10 mA in normal operation; above 50 mA the fuse trips within 1 second typical. Rated for a maximum voltage of 60 V and a maximum fault current of 40 A — sufficient for protecting 24 V or 48 V bus lines in telecom or industrial control boards where the upstream supply can deliver tens of amps short-circuit. Initial resistance is 15 Ohms min, post-trip resistance rises to 100 Ohms max — the series voltage drop at 10 mA is under 0.15 V in the untripped state, negligible for most logic-level loads.
Package, mounting, and operating range
Housed in a 0603 (1608 Metric) concave surface-mount package, 1.60 mm x 0.80 mm, 1.00 mm max thickness — standard pick-and-place footprint, no special reflow profile beyond the typical lead-free solder curve for 0603 passives. Operating temperature range is -40°C to +85°C — suited for indoor and outdoor equipment that sees ambient heat but not continuous engine-bay or industrial oven temperatures.
Regulatory approvals and supply status
Approved by cURus and TUV — accepted for North American and European equipment certification without additional component-level testing.