Vishay Precision Group Inc. announced that its Vishay Foil Resistors brand (VFR) has introduced a new series of military-qualified, ultra-high-precision Z1-Foil wrap-around chip resistors. Tested per EEE-INST-002 (Tables 2A and 3A, Film/Foil, Level 1) and MIL-PRF-55342, devices in the 303261 - 303266 series provide exceptional load-life stability of ±0.0025% typical after rated power at 70°C for 2,000 hours, low nominal TCR of ±0.2 ppm/°C from -55°C to +125°C, +25°C ref., PCR (ΔR due to self heating) of 5 ppm at rated power, and tight tolerances to ±0.02%.

The 303261 - 303266 series is based on VFR's next-generation Z1-Foil technology. The devices excel over all previous stability standards for precision resistors with an order of magnitude improvement in temperature stability, load-life stability, and moisture resistance. These benchmark levels of performance provide design engineers with the tools to build circuits not previously achievable, while reducing costs in the most critical circuits by eliminating the need for corrective circuitry.

In addition to their remarkable load-life stability of ±0.0025%, the resistors are noise-free and provide the utmost in ESD immunity, withstanding electrostatic discharges of 25 kV or more for increased reliability. The devices' solid element alloy is matched to the substrate, forming a single entity with balanced resistance versus temperature characteristics for an unusually low and predictable TCR over a wide temperature range from -55°C to +150°C. The new adhesive that holds the foil to the flat substrate withstands high temperatures, pulsing power, moisture incursions, shock and vibration, and low-temperature exposure, while still holding securely to the foil element. Resistance patterns are photo-etched into the element to permit the trimming of resistance values to very tight tolerances as low as 0.02%. 

"Even if an avionics/military/space application normally doesn't require the high precision, stability, and reliability provided by the EEE-INST-002 Bulk Metal® Foil resistor, these characteristics provide a higher margin of protection against 'black swan events' at a negligible additional cost," said Yuval Hernik, senior director of application engineering for VFR. "It isn't one single feature that makes the precision work; it's all the features working together that creates the overall stability and impacts the entire error budget."

Offered in six chip sizes from 0603 to 2512, the 303261 - 303266 series features a wide resistance range from 10 Ω to 75 kΩ. Any conceivable ohmic value within this range, to six digits, is available with no additional cost or lead time effect. The resistors feature power ratings to 400 mW at +70°C, a rise time of 1.0 ns, with effectively no ringing, a thermal stabilization time of <1 s (within 10 ppm of steady state value), current noise of <0.010 μVrms/V of applied voltage (<-40 dB), and a voltage coefficient of <0.1 ppm/V. The devices offer a noninductive (<0.08 μH), noncapacitive design, and are available in matched sets upon request. 

Samples and production quantities of the new Foil resistors are available now, with lead times of five working days for prototype samples, and eight weeks for standard orders. Pricing in the United States is $6.48 per piece. 

Further information about the 303261 - 303266 series and other Vishay Foil Resistors products is available at Follow Vishay Foil Resistors at