To meet the growing demand for precise, stable, and reliable resistors that can operate in harsh environments, Vishay Precision Group, Inc. (VPG) today announced that its Vishay Foil Resistors brand (VFR) has introduced a new ultra-high-precision through-hole Z-Foil resistor designed for high-temperature applications up to +200 degrees C. The Z201HT offers low TCR of ±1 ppm/degree C nominal from -55 to +200 degrees C, +25 degrees C ref.; tight tolerances to ±0.01%; and load-life stability to 0.1% after 1,000 hours of rated power at +200 degrees C.
The Z201HT is optimized for a wide variety of high-temperature applications, including geothermal measuring equipment, turbine engine control, and environmental test chambers in military, industrial, automotive, and down-hole drilling systems. Many analog circuits in these applications require passive components such as resistors to have a minimal drift from their initial values when operating above +175 degrees C and in humid environments.
In high-temperature applications, the most important factors are the end-of-life tolerance and, to a lesser extent, the initial tolerance. The Z201HT provides stabilities well under the maximum allowable drift required by customers’ specifications, through thousands of hours of operation under harsh conditions. In addition, the device features a special silicon-coated design without molding or encapsulation, helping to reduce signal distortion and increase clarity in signal processing.
“Resistors are the passive building blocks of an electrical circuit, which is why it’s so important that Bulk Metal Foil technology provides much more control over element formation and stability than thick film, metal film, or thin film technologies do,” said Yuval Hernik, senior director of application engineering for VFR. “When the application requires stability over time and load, initial accuracy, minimal change with temperature of more than 175 degrees C, resistance to moisture, and a number of other characteristics, only Vishay Foil Resistors have all the attributes needed.”
The Z201HT offers a resistance range from 10 Î© to 100 kÎ©, with any conceivable ohmic value within this range - to six digits - available with no additional cost or lead time effect. The resistor features rated power to 0.1 W at +200 degrees C, a rise time of 1 ns with effectively no ringing, a thermal stabilization time of <1 s (within 10 ppm of steady state value), current noise of â‰¤0.010 Î¼Vrms/V of applied voltage (<-40 dB), and a voltage coefficient of <0.1 ppm/V.
The Z201HT products receive stabilization processing such as repetitive thermal cycling and short-term power overloads to assure reliable service through the stresses of extreme operation. Offering the utmost in ESD immunity, the Z201HT withstands electrostatic discharges of at least 25 kV, for increased reliability, and offers a non-inductive (<0.08 Î¼H), non-capacitive design. The device is available with RoHS-compliant, lead (Pb)-free terminations or tin/lead-plated terminations. Samples and production quantities of the Z201HT are available now, with lead times of six weeks for large orders.