Thyristors provide enhanced surge protection in exposure environments

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 will continue to provide protection through multiple surge events without functional degradation.

Typical applications for Pxxx0MEL 5kA Series and Pxxx0FNL 3kA Series SIDACtor protection thyristors include:

• CATV amplifiers.
• Telecom base station equipment.
• Cell towers.
• UPS/AC high power distribution grids.
• Automotive battery charging systems.
• Solar power system DC/AC inverters.
• 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.” Pxxx0MEL series and Pxxx0FNL series SIDACtor protection thyristors offer these key benefits:

• Clamping that is superior to traditional MOV passive technology for AC line protection provides high power surge protection up to 3 or 5kA.
• Low on-state voltage condition ensures low thermal accumulation during long term events.

Unlike Gas Discharge Tubes (GDTs) or surge arrestors, these semiconductor crowbar devices have no wear-out mechanism, so they can withstand multiple surge events with minimal degradation, eliminating the need to dispatch service personnel to replace damaged equipment.