20LR450SU

Ptc Resettable Fuses Overview

The Littelfuse 20LR450SU is a PolySwitch resettable PTC fuse from the LR series, designed for strap mount installation with axial termination. It features a holding current of 4.5 A and a trip current of 8.9 A, rated for a maximum voltage of 20 V. The device has a minimum resistance of 28 mOhms and a maximum fault current rating of 100 A. Power dissipation is 2.5 W, with an operating temperature range from -40°C to +85°C. Physical dimensions are 24 mm in length, 9.9 mm in width, and 1 mm in height.

Ptc Resettable Fuses Feature Summary

• Provides reliable overcurrent protection by raising resistance as it heats to limit current flow
• Acts as a battery strap to protect rechargeable batteries from overcurrent, short circuits, and overcharging
• Offers low-resistance surface-mount functionality comparable to larger PolySwitch solutions

Ptc Resettable Fuses Applications

• Protection of rechargeable batteries from overcurrent and short circuits
• Overcurrent protection for automotive actuators, screens, and small motors
• Circuit protection for wiring harnesses and PCB components

Ptc Resettable Fuses Procurement Notes

Verify that the specific part number 20LR450SU matches the required electrical parameters, particularly the 4.5 A holding current and 20 V maximum voltage rating. Confirm the strap mount form factor and axial lead type align with the mechanical design. Ensure compliance with RoHS standards if required by the project specifications before finalizing procurement.

Ptc Resettable Fuses Selection Notes

Select this component when a low-profile, strap-mounted resettable fuse is needed for battery or circuit protection. The 4.5 A holding current and 20 V rating define the electrical limits. Consider the 28 mOhms resistance for power loss calculations. The -40°C to +85°C operating range suits standard electronic environments. Verify that the 100 A fault current rating exceeds potential surge currents in the application.

Ptc Resettable Fuses Part Context

This device belongs to the Littelfuse PolySwitch LR series of resettable PPTC fuses. These solid-state devices provide overcurrent protection for automotive, telecom, and power supply applications. The LR series includes various form factors such as surface-mount, radial-leaded, bladed, and battery-strap devices, all utilizing polymer technology to increase resistance during fault conditions.

Ptc Resettable Fuses Replacement Considerations

No public confirmed substitute part numbers are available.