Date: 21/01/2010
High-precision bulk metal foil resistors from Vishay
Vishay has introduced the H and HZ, a two new series of hermetically sealed, oil-filled Bulk Metal Foil resistors, which are suitable for the resistor applications such as resistance standards, feedback devices for operational amplifiers, precision voltage dividers, meter multipliers, precision bridge resistors, and decade voltage dividers.
The new H and HZ series resistors feature tolerances of 0.001 % (10 ppm), a resistance range of 5 Ohm to 1.84 MOhm, 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.
The hermetic sealing eliminates the ingress of moisture and oxygen, while the oil acts as a thermal conductor, thus eliminating the 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" family devices are also 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), such as temperature cycling, short-time overload, and accelerated load life, which are applicable to Bulk Metal Foil resistors, and minimizes the thermal EMF at the internal termination-to-resistor junction assembly.
"H" family devices also feature a electrostatic discharge protection up to 25 kV, a rise time of 1 ns, with essentially no ringing, current noise of < - 40 dB, thermal EMF of 0.05 µV/°C typical, and a voltage coefficient of < 0.1 ppm/V.
Device Specification Table: Specification H Series HZ Series (Z-Foil)
Typical TCR ± 2 ppm ± 0.2 ppm
Standard resistance range (higher/lower values available) 5 Ohm to 1.84 MOhm 5 Ohm to 1.1 MOhm
Availability: Now
For more details visit www.vishay.com