Current Limiting Devices (CLD) for improved performance in surge protection

Continuing to improve the support to customers adopting Current Limiting Devices (CLD) for their advanced surge and lightning protection solutions, CALY Technologies is proud to announce the release of Application Note AN-00038-17 “Improving Performance of Surge Protection Circuits with Current Limiting Devices.”

This application note demonstrates how the use of Current Limiting Devices (CLD) in surge and lightning protection circuits enables surpassing the performance offered by standard solutions, bringing unprecedented protection and compactness levels. This is illustrated with a widely-used circuit topology, the π-protection circuit, using a Gas Discharge Tube (GDT) and a Transient Voltage Suppressor (TVS).

CLD vs RES protection circuit

With such CLD-based surge and lightning protection circuit, the current through the TVS as well as its dissipated power remain at very low values (smaller and cheaper TVS), and are almost independent of the amplitude of the aggression surge. Additionally, the load voltage presents a predictable and smooth behavior, showing no spike, and remains independent of the amplitude of the aggressing surge.

graph CLD vs RES
Typical waveforms and conduction phases in the π protection circuit during a surge event using classical solution or Current Limiting devices

This Application Note is aimed at customers designing and deploying lightning and surge protection applications for audio/video, data and communication networks, by providing an application schematic and evidence on how the use of CLDs greatly improves performance.

For more information contact CALY Technologies or have a look at our CLD web page.