Varistors in SMD design provide high surge current capability

TDK Corporation has released two new varistor series in SMD design. The types of these series are offered for a wide range of operating voltages from 175VRMS to 460VRMS, corresponding to 225VDC to 615VDC. While the B72210M* series of surge devices, which are equivalent to S14 leaded disk varistors, provide a surge current capability of 6000A, the B72214M* series types, which are equivalent to S20 leaded disk varistors, have a high surge current capability of 10,000A. All types are created for a high operating temperature of a maximum of +125C and an exceptionally damp heat environment (85% relative humidity at +85C).

The new SMD high surge series is qualified to AEC-Q200. In terms of designs, all types are available in horizontal and vertical versions, which provide higher design flexibility. The horizontal version of the B72210M* series has dimensions of 22mm x 15mm x 11mm, while the B72214M* series has dimensions of 27mm x 18mm x 11mm (L x W x H). The vertical types have dimensions of 15mm x 10mm x 20mm and 18mm x 10mm x 25.5mm, respectively. This results in space saving compared to leaded varistors with the same performance.

Typical applications of these SMD surge protection components are onboard chargers, power supplies, frequency converters, photovoltaic systems and household appliances.