Vishay Announces New Z-Foil Molded Surface- Mount Resistors

Vishay Intertechnology, Inc. announced the new SMR1DZ and SMR3DZ ultra-high-precision Z-Foil molded surface-mount resistors, which provide a low typical TCR of ±0.05ppm/°C from 0°C to +60°C and ±0.2ppm/°C from −55°C to +125°C, an PCR ("ΔR due to self heating") of ±5ppm at rated power, tolerances to ±0.01%, and a load life ratio stability of 0.005%.

The new resistors are built on Vishay’s "Z- foil" technology, which provides a significant reduction of the resistive component’s sensitivity to ambient temperature variations (TCR) and applied power changes (PCR). Z-Foil is said to improve 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.

Featuring flexible terminations to ensure minimal stress transference from the PCB due to a difference in thermal coefficient of expansion (CTE), the devices offer a wide resistance range of 5 to 80kΩ, with any value at any tolerance available to designers for their specific application requirements.

Applications for the new devices include precision amplifiers; high-precision instrumentation; medical and automatic test equipment; high-end stereo equipment; electron beam scanning and recording equipment; and military, aerospace, and down-hole equipment and instrumentation.

The SMR1DZ features a power rating of 250mW at 70°C, while the SMR3DZ offers a power rating of 600mW at 70°C. Both devices have a load-life stability of ±0.005% for 2000 hours at 70°C; a low voltage coefficient of <0.1PPM/°C; current noise less than -40dB; and low thermal EMF of 0.05μv/°C. They offer a fast rise time of 1.0ns without ringing and feature a non-inductive (<0.08µH), non-hot-spot design. The resistors offer the utmost in ESD immunity, withstanding electrostatic discharges exceeding 25kV, for increased reliability.

Samples and production quantities of the new Z-Foil resistors are available now, with lead times of four to six weeks for larger orders. Pricing for U.S. delivery begins below $5 per unit.