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Thermally Protected

Thermally protected varistors integrate metal oxide varistors with thermally activated elements to provide overvoltage protection. By opening in response to heating from overvoltage events, the surge protective devices (SPDs) also prevent arcs and fires. Typical applications for the thermal cutoff devices include power strips, inverters, and uninterruptible power supplies. Littelfuse makes several versions of these innovative SPDs, including one with a semiconductor fuse. Find a solution by consulting our Circuit Protection Product Selection Guide.
  • Available with a wide range of operating voltages, from 75 V ac to 750 V ac
  • Available with a wide range of surge current ratings, from 6 kA 8/20 µs to 75 kA 8/20 µs
  • UL recognized
  • Certified lead-free, halogen-free, and RoHS compliant
  • Configured as square, tubular, and radial leaded surface mount SPDs
  • Optional leads can connect to indicators that show varistors have reached the end of their life and require replacing
  • Facilitate compliance with UL 1449 standard on use of SPDs
  • Integration of surge suppressor with thermal cutoff produces less inductance across a PCB than would using discrete components
  • Wave solderable

Thermally Protected Parts

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Thermally Protected Applications

An EV car body, chasis, and tires pulled apart in a vertical stack above a red lightning bolt
DC/DC Conversion

EVs rely on dc–dc converters to step up or step down current from batteries. This block diagram shows the power conversion solutions Littelfuse

Thermally Protected Resources

Thermally Protected Featured Products