AVX – Zinc oxide varistors for ESD protection feature very low leakage current

AVX has expanded its zinc oxide- based series of varistors for ESD protection to include a version which features a low maximum leakage current of 1μA, helping to extend battery run-time in portable devices.

Intended for use in applications requiring low power consumption, the UltraGuard series also offers a higher voltage rating and a faster ESD response time than any other product on the market.

The UltraGuard series multi-layer ceramic varistors feature non-linear, bi-directional voltage- current characteristics similar to back-to-back zener diodes with an EMC capacitor in parallel. The UltraGuard devices, however, offer many electrical advantages over zener diodes, including:
• better repetitive strike capability
• higher in-rush current capability
• faster turn-on-time
• inherent EMI/RFI attenuation
• a markedly smaller footprint

The robust UltraGuard series varistors are rated to survive 1,000 ESD contact strikes of 15kV.

They are supplied as discrete chips in the 0402, 0603, and 0805 sizes; as two-element packages in 0405 and 0508 sizes; and as four element 0612 packages. Various capacitance options are available from the lowest at 40pF up to the highest at 3,000pF. The choice of working voltages ranges from 3V to 32V DC, and peak currents range up to 150A.


  • EMI/RFI filtering in the Off state
  • Operating temperature range: -55°C to 125°C with no derating
  • Range of energy ratings: 0.02J to 0.4J


  • Battery-powered devices
  • High clock-speed ICs
  • Low-voltage power converters
  • Power supervisors
  • Laser diodes