Polymeric PTC in a 0603 footprint
The 0603L002/60YR is a Littelfuse POLY-FUSE® polymeric PTC resettable fuse in the 0603 (1608 Metric) concave surface-mount package. It protects low-current signal or power rails against overcurrent faults by switching from a low-resistance state to a high-resistance state when the trip current is exceeded. Hold current (Ih) is 20 mA maximum — the fuse remains conductive below this threshold. Trip current (It) is 60 mA, and the typical time to trip at 25°C is 1 second, meaning the device clears a fault quickly enough to protect downstream components without nuisance tripping on inrush.
Fault ratings and resistance profile
Maximum voltage rating is 60V, and the device can withstand a fault current up to 40 A — sufficient for most low-power DC rails in telecom, industrial control, or battery-management circuits. The initial series resistance (Ri) is at least 12 Ohms, rising to a maximum of 70 Ohms after a trip event (R1). This post-trip resistance limits the leakage current during the fault and resets when power is removed and the device cools. The hold and trip currents derate with ambient temperature — at the upper end of the range the effective hold current is lower, so the circuit designer should consult the derating curve for the specific application.
Active production and sourcing posture
Regulatory approvals include cURus and TUV, which certify the device for use in equipment sold in North America and the EU respectively.