Vishay Foil Resistors Are Not Restricted to Standard Values, and Vishay Can Supply “As Required” Values (e.g., 9.997 kΩ vs. 10 kΩ) at no Extra Cost or Delivery Time
MALVERN, Pa. — April 17, 2009 — Vishay Intertechnology, Inc. (NYSE: VSH) today announced four new conformally coated, cost-effective, high-precision Bulk Metal® Foil and Z-Foil resistors that utilize a unique manufacturing process that results in extremely high accuracy and the fastest rise time when compared to other resistor technologies: 1 ns, effectively without ringing. The Foil VSH
and Z-Foil VSHZ
offer a low typical TCR of ± 2 ppm/°C and ± 0.2 ppm/°C from . 55 °C to +125 °C, + 25 °C ref, respectively. The resistors offer tolerances to ± 0.01 %, and a load life stability of 0.01 % (100 ppm) at + 70 °C after 2000 hours at rated power.
The devices released today offer a broad resistance range of 5 Ω to 120 kΩ, a voltage coefficient of < 0.1 ppm/V, and a low current noise of < -42 dB. Like all Vishay Foil resistors, the VSH/Z and VSC/Z are not restricted to standard values, and can be supplied with “as required” values (e.g. 9.997 kΩ vs. 10 kΩ) at no extra cost or delivery time. The resistors feature a power rating of 300 mW at + 70 °C, with a maximum working voltage of 300 V.
While other resistor technologies can take several seconds or even minutes to achieve a steady-state thermal stabilization, the VSH/Z and VSC/Z have an almost instantaneous thermal stabilization time of < 1 second. Built to handle unconventional environmental conditions with minimal drift, these are the ultimate resistors for analog applications. Their construction guarantees a high level of reliability, and provides high resistance to thermal shock, moisture, mechanical shock, and vibrations.
Typical applications for the resistors will include dc-to-dc converters, feedback circuits, and high-precision amplifiers in test and measurement instrumentation; laboratory, industrial, and medical systems; electron beam applications; commercial and military avionics; audio systems; and down-hole drilling instrumentation.
The devices are the result of a unique concept in resistor manufacturing. A proprietary Bulk Metal Foil element with known and controllable properties is applied to a special ceramic substrate. A resistive pattern is then photoetched by an ultra-fine technique developed by Vishay. The devices’ etched planar construction results in the extremely low and reproducible reactance needed for high-frequency and pulse applications.
In applications requiring precise and stable resistors, TCR needs to be low over the full temperature range of the application. Only Z-Foil resistors, such as the VSHZ
, provide a very low absolute TCR that changes very little over the full temperature range of − 55 ° C to + 125 °C and beyond.
Vishay Foil resistors are uniquely enhanced by Post Manufacturing Operations (PMO) exercising after the manufacturing cycle is complete. Some of these exercises are a standard part of the manufacturing cycle and are only repeated during the PMO cycle to gain added stability or confidence in the product. The Foil resistor load-life curve shows an increase in resistance from the first load application, but flattens out to no change after 500 to 1000 hours of loading. This knee in the load-life curve can be removed by a special accelerated load-life operation performed by Vishay, resulting in a flat response immediately after installation. Other resistive devices show a continuous change when subjected to these same stresses and are driven out of tolerance. Contact Vishay Foil Engineering sales (Foil@vishay.com) for assistance in specifying the PMO routine to be used in your application.
The VSH/Z and VSC/Z resistors withstand electrostatic discharges up to 25 kV for increased reliability and offer a non-inductive (< 0.08 μH), non-capacitive design. The devices are available with lead (Pb)-free and tin/lead alloy terminations.
Samples and production quantities of the new resistors are available now, with lead times of 72 hours for samples, and four weeks for standard orders.
Vishay Precision Group Inc. has ceased to be a subsidiary of Vishay Intertechnology Inc. and is an independent publicly owned company.