VPG announces on-site bulk metal foil resistor trimming at Digi-Key

USA: Vishay Precision Group Inc. has opened a new Vishay Foil Resistors (VFR) Precision Center within Digi-Key Corp., a global full-service provider of both prototype/design and production-quality electronic components.

Digi-Key can now build and ship VFR surface-mount precision resistors -- with no minimum quantities -- in 24 to 48 hours, including VFR's popular new Bulk Metal® Foil VSMP (Z-Foil Technology) and VSM series resistors. These resistors are supplied to any resistance value in their range, with no standard value restrictions.

Digi-Key is a valued distributor of VFR's most popular precision resistor models used in critical circuits for avionics, military, and space (AMS) applications. They are also used in high-volume automatic test equipment, alternative energy, audio, automotive, medical, and energy-exploration applications. With an on-site Precision Center, Digi-Key now trims these resistors' elements to the exact customer-requested resistance -- specified to six-digits (e.g., 998.995 ohms vs. 1 kilohm) -- while maintaining all the inherent performance characteristics of Bulk Metal Foil technology.

"Typically, resistor manufacturers will supply resistor samples of a few pieces, but only with standard E series values," said Yuval Hernik, senior director for application engineering, Vishay Foil Resistors.

"If a customer requires a slightly higher quantity for prototypes, they usually have to purchase a full reel of resistors for each value. With a Precision Center on site, Digi-Key is helping to set a new standard by shipping the exact number of resistors needed of the precise resistance value and tolerances required; and they can do this in just a few days. For designers, this provides an invaluable source for small-quantity prototype runs and quick changes prior to full production."

With an on-site Precision Center, Digi-Key is able to ship VFR's newer VSMP and VSM wraparound surface-mount chip resistors from its own finishing operations. Based on Bulk Metal Z-Foil and Classic Foil technologies, respectively, both series offer initial tolerances as low as 0.01% with load-life stability from 0.005% (50 ppm) after 2,000 hours with rated power applied at +70 °C, and 0.01% (100 ppm) after 10,000 hours. TCRs as low as 0.05 ppm/°C from 0 °C to +60 °C provide unprecedented thermal stability and assure automatic TCR tracking of any number of resistors, even across separate circuit boards inside electronic equipment. The devices' unique construction permits uniform heat dissipation and minimizes the effects of extreme environments.

The resistors are noise-free and provide ESD protection of 25 kV or more for increased reliability. Prototyping with these highest available stability resistors in exact required values enables designers to take prototype circuits directly to full-scale environmental and life tests instead of the usual two-stage process of initial room temperature evaluation followed by subsequent ordering of more precise parts for full-scale testing.