Enhanced 3kA and 5kA surge protection thrysistors enhance clamping for AC line protection

January 11, 2018 // By Nick Flaherty
Littelfuse has launched two series of protection thyristors optimised to protect equipment located in high exposure environments from severe overvoltage transients

The Pxxx0MEL 5kA Series (above) and Pxxx0FNL 3kA Series SIDACtor protection thyristors offer enhanced reliability across multiple high energy surge events. Unlike many non-semiconductor-based high power protective products, which can experience functional degradation after only a few surge events, the Pxxx0MEL and Pxxx0FNL Series are semiconductor-based components and provide protection through multiple surge events without functional degradation.

The parts are aimed at AC line applications in CATV amplifiers, telecom base station equipment, cell towers, UPS/AC high-power distribution grids, automotive battery charging systems, solar power system DC-AC inverters and uninterruptible battery backup systems.​

“The Pxxx0MEL 5kA Series and Pxxx0FNL 3kA Series SIDACtor protection thyristors offer on-state voltage values that are much lower than the arc voltage of a traditional gas discharge tube. This low on-state voltage means they can handle much higher surge currents,” said Jack Tung, Global Product Marketing Manager at Littelfuse. “They also offer a much lower voltage threshold than the clamping voltage of a metal oxide varistor, and can be used in series with clamping devices such as varistors or TVS didoes for protecting AC power input lines.”

The low on-state voltage condition ensures low thermal accumulation during long-term events and unlike gas discharge tubes (GDTs) or surge arrestors, the semiconductor crowbar design has no degradation mechanism, so they can withstand multiple surge events with minimal degradation, eliminating the need to dispatch service personnel to replace damaged equipment.

The Pxxx0MEL 5kA Series SIDACtor protection thyristors in TO-218 packaging are available in tube pack in quantities of 250, with 25 devices per tube and 10 tubes per box. The Pxxx0FNL 3kA Series SIDACtor protection thyristors in TO-262M packaging are available in tube pack in quantities of 500 (50 per tube) or in tray pack in quantities of 100.

www.littelfuse.com