PolySwitch RXEF Resettable Fuse, 72V DC, 200mA-400mA, 2.2s

The Littelfuse PolySwitch RXEF series is a family of radial-leaded polymer positive temperature coefficient (PPTC) resettable fuses, designed to provide reliable overcurrent protection for sensitive electronic circuits. The RXEF020 model offers robust performance with a 72V DC voltage rating, making it suitable for a wide range of industrial and consumer applications where power surges and fault conditions must be managed. This device automatically resets itself after the fault is cleared and the power is cycled, eliminating the need for manual replacement and reducing maintenance costs and downtime.

Core Features & Applications

This component is essential for protecting devices such as satellite video receivers, computer motherboards, modems, and USB hubs. It is also widely used in industrial controls, transformers, battery packs, and various communication equipment including phones, fax machines, and analogue/digital line cards. Its compatibility with high-volume electronics assembly processes makes it an efficient choice for manufacturers.

The fuse operates by transitioning from a low-resistance to a high-resistance state when an overcurrent condition occurs, effectively limiting the fault current. It has a holding current of 200mA and will trip at 400mA, with a typical time-to-trip of 2.2 seconds under specified conditions. This precise response helps prevent damage to downstream components.

Certifications & Reliability

Constructed for durability and safety, the RXEF series is UL recognised, CSA approved, TÜV approved to EN 60730-1, and CQC approved to several GB standards. It can operate reliably across an extensive ambient temperature range from -40°C to +85°C, ensuring performance in challenging environments. Its compact, round form factor with a 5.8mm lead spacing facilitates easy integration into PCB designs.

Choosing the Littelfuse PolySwitch RXEF resettable fuse means investing­