Date: 07/01/2010

Hermetically sealed, oil-filled Bulk Metal Foil resistors from Vishay

Vishay has introduced the H and HZ, a two new series of secondary-standard, hermetically sealed, oil-filled Bulk Metal Foil resistors that provides high precision, stability, and speed.

The hermetic sealing eliminates the ingress of moisture and oxygen, while the oil acts as a thermal conductor, thus eliminating long-term degradation elements of unsealed resistors, while at the same time allowing the device to accept short periods of overload without degradation.

The Z-Foil technology provides a reduction of the resistive components, sensitivity to ambient temperature variations (TCR) and applied power changes (PCR). When combined with the hermetic sealing and oil filling, the HZ Series resistors become the most precise and stable resistors available. They are used as the most precise secondary standards for ultra precision metrology.

The H series is available with laboratory and metrology level precision and long-term stability with additional in-house oriented processes such as chip stabilization, special TCR plotting, additional treatments for ultra stability and special post manufacturing operations (PMO).

The H and HZ series feature tolerances of 0.001 % (10 ppm), a resistance range of 5 Ohm to 1.84 M Ohm, shelf-life stability of 2 ppm (±0.0002 %) for at least 6 years (unaffected by humidity), and a rise time of < 1 ns. Maximum TCR ranges from ± 2 ppm/°C for the H series to ± 0.2 ppm/°C for the Z-Foil HZ series.

With the H and HZ series resistors, only a minimal shift in resistance value will occur during their entire lifetime. Most of the shift takes place during the first few hundred hours of operation and virtually no change is noted thereafter. This change can be eliminated with additional PMO.

Availability: Now in samples and production quantities

For more details visit www.vishay.com