TRF250-120S-B-0.5

Ptc Resettable Fuses Overview

The Littelfuse TRF250-120S-B-0.5 is a PolySwitch resettable PTC fuse designed for circuit protection. It features a holding current of 120 mA and a trip current of 240 mA, with a maximum voltage rating of 60 VDC (250 VAC internal). The device has a maximum rated current of 3 A and an initial resistance of 4 Ohms minimum, rising to 16 Ohms maximum after tripping. It operates within a temperature range of -40°C to +85°C. Dimensions are 6.50 mm x 4.60 mm x 10.00 mm with a 5.00 mm lead spacing.

Ptc Resettable Fuses Feature Summary

• Provides automatic overcurrent protection through polymer PTC technology that resets upon cooling.
• Offers dual certification from CSA, TUV, and UL agencies for global compliance.
• Features radial through-hole mounting with a disk-style package for PCB integration.

Ptc Resettable Fuses Applications

• Building and home automation circuits
• Portable electronic device power lines
• Peripheral equipment interface protection

Ptc Resettable Fuses Procurement Notes

Verify the specific suffix 'S' indicates the radial disk style configuration distinct from other TRF250 variants. Confirm RoHS3 compliance status and MSL Level 1 classification during sourcing. Ensure the supplier provides valid UL/CSA/TUV recognition documentation matching this exact part number for regulatory approval processes.

Ptc Resettable Fuses Selection Notes

Select this component when a 120 mA hold current is required for low-power signal or data line protection. The 60 VDC rating suits battery-powered applications. Consider the 16 Ohms max trip resistance for voltage drop calculations in sensitive logic circuits. Verify ambient temperature conditions do not exceed the +85°C operational limit for reliable performance.

Ptc Resettable Fuses Part Context

This part belongs to the Littelfuse TRF250 series of PolySwitch resettable fuses. It serves as a reusable alternative to traditional one-time fusible links. The series is engineered for compact PCB spaces, offering reliable overcurrent interruption without permanent circuit damage. It replaces standard fuses in applications requiring frequent reset capability.

Ptc Resettable Fuses FAQ

What is the difference between initial and trip resistance?

The initial resistance is 4 Ohms minimum before activation. After tripping due to overcurrent, the resistance increases to a maximum of 16 Ohms to limit current flow.

Is this component suitable for AC circuits?

Yes, it is rated for 250 VAC internally, though the primary DC rating is 60 VDC. Ensure the AC application stays within these voltage limits.