Littelfuse – Varistors provide high surge protection at temperatures up to 125°C


The HMOVTM varistor series from Littelfuse is for applications requiring the ability to absorb high surge energy and to operate at high temperatures up to 125°C.

The maximum peak surge current is rated at up to 10kA for an 8/20μs pulse. This is sufficient to protect against indirect lightning strikes, switching surge transients and abnormally fast transients.

The HMOV series also succeeds in combining high-temperature operation with isolation from high voltages, offering 2,500V of isolation at a temperature of 125°C.

The varistors are available in three disc sizes: 10mm, 14mm and 20mm, and with straight leads, outer crimped leads and inner crimped leads.


  • Complies with 1,000 cycle, -55°C to 125°C thermal shock cycling test
  • Continuous voltage range:
    - 14V to 825V DC
    - 11V to 625V AC
  • >1,000MΩ insulation resistance


  • Industrial automation controls
  • Solar power inverters
  • Security systems
  • Fire alarms and smoke detectors
  • LED lighting
  • Telecoms power supplies
  • Power supplies for harsh environments