Ultrahigh-precision resistor renders accuracy, reliability

To meet the demand for ultrahigh-precision resistors in high-reliability applications, Vishay Intertechnology Inc. has introduced VSA101 axial Bulk Metal Z-Foil resistor. The new device provides a low absolute TCR of ±0.05ppm/°C from 0°C to +60°C and ±0.2ppm/°C from -55°C to +125°C, +25°C ref., an excellent polymerase chain reaction (PCR) ("ΔR due to self heating") of ±5ppm at rated power, a tolerance of ±0.005 percent, and a load life stability of ±0.005 percent.

The new resistor is built on Vishay's breakthrough "Z-foil" technology, which provides a significant reduction of the resistive component's sensitivity to ambient temperature variations and applied power changes. Z-Foil improves stability by an order of magnitude compared to any other resistor technology, allowing designers to guarantee a high degree of accuracy in fixed-resistor applications.

Composition strength
The VSA101's construction consists of silicone rubber encapsulation that isolates the resistive element from external stresses, while its mold case affords maximum protection against all environmental conditions. The device is optimized for signal conditioning and high-precision instrumentation amplifiers for ultrastable and high-reliability products, in medical, test and measurement, military, aerospace, laboratory, down-hole and high-end stereo equipment.

What it offers
The VSA101 allows designers to achieve a much better performance by combining a range of ultrahigh-precision specifications in a single device. It has a load-life stability of ±0.005 percent for 2000hr at +70°C at rated power; a power rating of 0.3W at +125°C; a low voltage coefficient of D;0.1PPM/V; current noise of D;-40dB; and thermal EMF of 0.05?V/°C. The resistor offers a fast rise time of 1.0ns without ringing and features a non-inductive (D;0.08?H), noncapacitive design.

The device offers the utmost in ESD immunity, withstanding electrostatic discharges exceeding 25KV, for increased reliability. Within a resistance range of 5Ω to 100KΩ, any value at any tolerance is available through calibration at no additional cost.

Samples and production quantities of the VSA101 ultrahigh-precision resistor are available now, with lead times of 72hr for samples, and three weeks for standard orders.