High-Surge Series Multilayer Varistors

TDK Corporation presents the high-surge series of EPCOS multilayer varistors. These are characterized by their high-surge current capability, ranging from one surge up to 5000 A to ten surges up to 3500 A, with a pulse of 8/20 µs, and an operating voltage up to 65 V_DC. In addition, the SMD components are very compact and are available in case sizes EIA 1210 through EIA 2220 and require significantly less space than wired types or semiconductor-based solutions, while offering the same performance and reliability.

A high-performance ceramic material set and an improved component design have made the further miniaturization possible. This means that, in comparison with conventional technologies, current densities of three times higher can be achieved. On this basis, TDK now manufactures protection components in the EIA 1210 case size that offer the same performance as existing EIA 2220 types, which are three times larger. Despite their compact design, the maximum energy absorption for EIA 2220 components is about 15 J for a pulse of 2 ms.

In addition, the rugged EPCOS multilayer varistors are highly resistant to thermo-mechanical stress and offer an extremely high-surge current capability even at 125°C, a temperature at which other technologies can only be operated with derating. The protection components are designed for a lead-free reflow soldering process. Applications for the EPCOS multilayer varistors include power supplies for telecommunication systems and power-over-Ethernet (PoE) systems.